<PAGE>


                                   EXHIBIT 4.2

     THIS WARRANT HAS NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS
     AMENDED (THE "ACT") OR APPLICABLE STATE SECURITIES LAWS (THE "STATE ACTS")
     AND MAY NOT BE SOLD, PLEDGED, HYPOTHECATED, DONATED, ASSIGNED OR OTHERWISE
     TRANSFERRED (WHETHER OR NOT FOR CONSIDERATION), IN WHOLE OR IN PART, BY THE
     HOLDER, WITHOUT AN EFFECTIVE REGISTRATION STATEMENT THEREOF UNDER SUCH ACT
     AND APPLICABLE STATE ACTS OR THE ISSUANCE TO THE COMPANY OF AN OPINION OF
     COUNSEL SATISFACTORY TO COUNSEL TO THE COMPANY AND/OR SUBMISSION TO THE
     COMPANY OF SUCH EVIDENCE AS MAY BE SATISFACTORY TO COUNSEL TO THE COMPANY,
     IN EACH SUCH CASE, TO THE EFFECT THAT ANY SUCH TRANSFER SHALL NOT BE IN
     VIOLATION OF THE ACT AND THE APPLICABLE STATE ACTS.

     THE SHARES OF COMMON STOCK ISSUABLE UPON THE EXERCISE HEREOF HAVE NOT BEEN
     REGISTERED UNDER THE ACT OR APPLICABLE STATE ACTS AND THIS WARRANT MAY NOT
     BE EXERCISED AND THE COMMON STOCK ISSUABLE UPON THE EXERCISE HEREOF MAY NOT
     BE SOLD, PLEDGED, HYPOTHECATED, DONATED, ASSIGNED OR OTHERWISE TRANSFERRED
     (WHETHER OR NOT FOR CONSIDERATION), IN WHOLE OR IN PART, BY THE HOLDER,
     WITHOUT AN EFFECTIVE REGISTRATION STATEMENT THEREOF UNDER SUCH ACT AND
     APPLICABLE STATE ACTS OR THE ISSUANCE TO THE COMPANY OF AN OPINION OF
     COUNSEL SATISFACTORY TO COUNSEL TO THE COMPANY AND/OR SUBMISSION TO THE
     COMPANY OF SUCH EVIDENCE AS MAY BE SATISFACTORY TO COUNSEL TO THE COMPANY,
     IN EACH SUCH CASE, TO THE EFFECT THAT ANY SUCH EXERCISE OR TRANSFER SHALL
     NOT BE IN VIOLATION OF THE ACT AND THE APPLICABLE STATE ACTS.

                                  WARRANT NO. A-

                       TO PURCHASE                 SHARES
                                   ---------------

                                 OF COMMON STOCK
                                       OF
                               AMERICASBANK CORP.
                            (a Maryland Corporation)

                        Transferable and Exercisable Only
                        Upon Conditions Herein Specified

                        Exercisable after April 1, 2000,
                        Void after 5:00 O'Clock P.M. EST,

<PAGE>


                              on September 1, 2008

     AMERICASBANK CORP., a Maryland corporation (the "Company"), hereby
certifies that                                                     , such
               ----------------------------------------------------
holder's heirs, personal representatives, successors and/or assigns, registered
on the books of the Company maintained for such purposes as the registered
holder hereof (the "Holder"), is entitled to purchase from the Company the
number of fully paid and non-assessable shares of Common Stock of the Company
stated above, par value $0.01 per share (the "Shares"), at the purchase price of
$10.00 per Share (the "Exercise Price") (the number of Shares and Exercise Price
being subject to adjustment as hereinafter provided), upon the terms and
conditions herein provided.

     1.   EXERCISE OF WARRANTS.

          (a) Subject to the provisions of subsection (b) of this Section 1 and
Section 4 hereof, upon presentation and surrender of this Warrant, with the
attached Purchase Form duly executed, at the office of the Company at 3621 East
Lombard Street, Baltimore, Maryland 21224, or at such other place as the Company
may designate by notice to the Holder hereof, together with a check payable to
the order of the Company in the amount of the Exercise Price times the number of
Shares being purchased, the Company shall deliver to the Holder hereof, as
promptly as practicable, a certificate representing the Shares being purchased.
This Warrant may be exercised in whole or in part; and, in case of exercise
hereof in part only, the Company, upon surrender hereof, will deliver to the
Holder a new Warrant of like tenor entitling the Holder to purchase the number
of Shares as to which this Warrant has not been exercised.

          (b) This Warrant may be exercised in whole or in part at any time
after April 1, 2000, and shall be void after 5:00 p.m. EST, on September 1,
2008.

     2. RIGHTS AND OBLIGATIONS OF WARRANT HOLDER. No Holder of this Warrant
shall be entitled to any of the rights of a shareholder of the Company,
including, but not limited to, to the extent applicable, the right to vote, give
or withhold consent to any action by the Company, receive dividends,
subscription rights, or otherwise, nor shall anything contained in this Warrant
be construed to confer upon the Holder of this Warrant, as such, any of the
rights of a shareholder of the Company; provided, however, that upon exercise of
this Warrant, such Holder shall, for all purposes, be deemed to have become the
holder of record of such Shares on the date on which this Warrant, together with
a duly executed Purchase Form, was surrendered and payment of the Exercise Price
was made, irrespective of the date of delivery of any Share certificate. The
rights of the Holder of this Warrant are limited to those expressed herein and
the Holder of this Warrant, by its acceptance hereof, consents to and agrees to
be bound by and to comply with all the provisions of this Warrant, including,
without limitation, all the obligations imposed upon the Holder hereof by
Section 4 hereof. In addition, the Holder of this Warrant, by accepting the
same, agrees that the Company may deem and treat the person in whose name this
Warrant is registered on the books of the Company maintained for such purpose as
the absolute, true and lawful owner for all

<PAGE>

purposes whatsoever, notwithstanding any notation of ownership or other writing
thereon, and the Company shall not be affected by any notice to the contrary.

     3. SHARES UNDERLYING WARRANTS. The Company covenants and agrees that all
Shares delivered upon the exercise of this Warrant shall, upon delivery and
payment therefor, be duly and validly authorized and issued, fully-paid and
non-assessable, and free from all taxes, liens and charges with respect to the
purchase thereof.

     4. RESTRICTIONS ON EXERCISE; DISPOSITION OF WARRANTS OR SHARES. The Holder
of this Warrant, by its acceptance hereof, hereby represents and warrants that
such Holder understands and agrees that (a) the Warrant and the Shares issuable
upon the exercise of this Warrant have not been registered under either the
Securities Act of 1933, as amended (the "Act"), or applicable state securities
laws (the "State Acts"), and the Company has no obligation to register the
Warrant or such Shares; (b) the Warrant may be exercised only if the Shares
underlying the Warrant have been registered under the Act and the applicable
State Acts or upon the issuance to the Company of an opinion of counsel
satisfactory to counsel to the Company and/or submission to the Company of such
evidence as may be satisfactory to counsel to the Company, in each such case, to
the effect that any such exercise shall not be in violation of the Act and the
applicable State Acts; (c) this Warrant may not be sold, pledged, hypothecated,
donated, assigned or otherwise transferred (whether or not for consideration),
in whole or in part, by the Holder, unless the Warrant has been registered under
the Act and the applicable State Act or upon the issuance to the Company of an
opinion of counsel satisfactory to counsel to the Company and/or submission to
the Company of such evidence as may be satisfactory to counsel to the Company,
in each such case, to the effect that any such transfer shall not be in
violation of the Act and the applicable State Acts and (d) the Shares issuable
upon the exercise of this Warrant may not be sold, pledged, hypothecated,
donated, assigned or otherwise transferred (whether or not for consideration),
in whole or in part, by the Holder, unless the Shares have been registered under
the Act and the applicable State Acts or upon the issuance to the Company of an
opinion of counsel satisfactory to counsel to the Company and/or upon submission
to the Company of such evidence as may be satisfactory to counsel to the
Company, in each such case, to the effect that any such transfer shall not be in
violation of the Act and the State Acts. The Holder hereby agrees that the
Company's obligation to deliver Shares upon exercise of this Warrant is subject
to the requirement that the Holder deliver to the Company, if requested by the
Company, such certificates, documents or other information as the Company or its
counsel may reasonably request for the purpose of establishing compliance with
the Act and applicable State Acts.

     5. ADJUSTMENTS. The number of Shares purchasable upon the exercise of this
Warrant and the Exercise Price therefor is subject to adjustment from time to
time upon the occurrence of any of the events enumerated below.

          (a) Effect of Stock Changes. In the event that at any time during the
term of this Warrant the Company shall (i) pay a dividend in shares of its
Common Stock,

<PAGE>

(ii) subdivide outstanding shares of its Common Stock into a greater number of
shares, or (iii) combine outstanding shares of its Common Stock into a smaller
number of shares, the amount of shares purchasable upon the exercise of this
Warrant immediately prior thereto shall be adjusted so that the Holder shall be
entitled to receive upon exercise of the Warrant that number of shares of Common
Stock which such Holder would have owned or would have been entitled to receive
after the happening of such event had such Holder exercised the Warrant
immediately prior to the record date, in the case of such dividend, or the
effective date, in the case of any such subdivision or combination and the
Exercise Price shall be proportionately adjusted. An adjustment made pursuant to
this subparagraph (a) shall be made whenever any of such events shall occur, but
shall become effective retroactively after such record date or such effective
date, as the case may be, if this Warrant is exercised between such record date
or effective date and the date of happening of any such event.

          (b) Merger; Dissolution; Etc. In the event that at any time during the
term of this Warrant there shall be (i) any capital reorganization or
reclassification of the Common Stock of the Company, (ii) a consolidation or
merger of the Company with another entity (other than a merger with a subsidiary
in which merger the Company is the continuing corporation and which does not
result in any reclassification or change of the Shares issuable upon exercise of
the Warrant); (iii) a share exchange in which the Common Stock of the Company
will be acquired; or (iv) the sale or lease of all or substantially all of the
assets of the Company; then, as a condition of the reorganization,
reclassification, consolidation, merger, share exchange, sale or lease, lawful
and fair provision shall be made whereby the Holder of this Warrant after the
transaction shall have the right to purchase and receive, upon the basis and
upon the terms and conditions specified in this Warrant and in lieu of the
shares of Common Stock of the Company purchasable and receivable immediately
prior to the transaction upon the exercise of the rights represented by this
Warrant, the shares of stock, securities or assets that may be issued or payable
with respect to or in exchange for a number of outstanding shares of Common
Stock equal to the number of shares of Common Stock purchasable and receivable
immediately prior to the transaction upon the exercise of the rights represented
by the Warrant if the reorganization, reclassification, consolidation, merger,
share exchange, sale or lease had not taken place. Appropriate provisions shall
be made in connection with a reorganization, reclassifica-tion, consolidation,
merger, share exchange, sale or lease with respect to the rights and interests
of the Holder of this Warrant to the end that the provisions of this Warrant
(including, without limitation, provisions for adjustments of the Exercise Price
and of the number of Shares purchasable upon exercise of the Warrant) shall
immediately after the transaction be applicable as nearly as possible to any
shares of stock, securities or assets deliverable immediately after the
transaction upon the exercise of the Warrant. The Company shall not effect any
consolidation, merger, share exchange, sale or lease unless, prior to the
consummation of the transaction, the successor entity (if other than the
Company) resulting from the consolidation or merger, the entity acquiring the
shares of Common Stock in the share exchange, or the entity purchasing or
leasing the assets, assumes by written instrument executed and delivered to the
Company, the obligation to deliver to the Holder of this

<PAGE>

Warrant the shares of stock, securities or assets in accordance with the
foregoing provisions that the Holder may be entitled to purchase.

          (c) Notice of Change in Warrant. Whenever the number of Shares
purchasable hereunder or the Exercise Price therefor is adjusted as herein
provided, the Company shall cause to be mailed to the Holder a notice (i)
stating that the number of Shares purchasable upon exercise of this Warrant
and/or the Exercise Price has been adjusted, (ii) setting forth the adjusted
number of Shares purchasable and/or the adjusted Exercise Price upon the
exercise of this Warrant and (iii) showing in reasonable detail the computations
and the facts upon which such adjustments are based. The Company's board of
directors, acting in good faith, shall determine the calculation.

          (d) Other Notices. In case at any time (i) the Company pays any
dividends payable in stock upon its Common Stock or makes any distributions
(other than regular cash dividends) to the holders of its Common Stock; (ii) the
Company offers for subscription pro rata to the holders of its Common Stock any
additional shares of stock of any class or any other rights; (iii) there is a
capital reorganization or reclassification of the Common Stock of the Company,
or a consolidation or merger of the Company with, or a share exchange in which
the Common Stock of the Company is being acquired by, or a sale or lease of all
or substantially all of its assets to, another entity; or (iv) there is a
voluntary or involuntary dissolution, liquidation or winding up of the Company;
then, in any one or more of these cases, the Company shall cause to be mailed to
the Holder of this Warrant notice of the date on which (i) the books of the
Company close or a record is taken for the dividend, distribution or
subscription rights, or (ii) the reorganization, reclassification,
consolidation, merger, share exchange, sale, lease, dissolution, liquidation, or
winding up shall take place. The notice also shall specify the date as of which
the holders of the Common Stock of record shall participate in dividend,
distribution or subscription rights, or shall be entitled to exchange their
Common Stock for securities or other property deliverable upon the
reorganization, reclassification, consolidation, merger, share exchange, sale,
lease, dissolution, liquidation, or winding up. The notice shall be given at
least ten (10) days prior to the closing of the transaction in question and not
less than ten (10) days prior to the record date or the date on which the
Company's transfer books are closed with respect to the transaction. Failure to
give the notice, or any defect in the notice, shall not affect the legality or
validity of any transaction covered or to be covered in the notice. On the date
of the dissolution, liquidation or winding up of the Company, if it actually
occurs, this Warrant and all rights existing under this Warrant shall terminate.

          (e) Form of Warrant. Irrespective of any adjustment or change in the
number or class of shares purchasable under this Warrant or in the Exercise
Price per Share, this Warrant may continue to express the Exercise Price and the
number and class of Shares purchasable upon exercise of this Warrant as the
Exercise Price and the number and class of Shares purchasable were expressed in
this Warrant when it was initially issued.

<PAGE>

     6. FRACTIONAL SHARES. The Company shall not be required to issue any
fraction of a Share upon the exercise of this Warrant. In lieu of issuing a
fraction of a Share remaining after exercise of this Warrant as to the full
shares covered hereby, the Corporation shall make a cash payment for any
fraction of a Share equal to the same fraction of the Exercise Price.

     7. LOSS OR DESTRUCTION. Upon receipt of evidence satisfactory to the
Company of the loss, theft, destruction or mutilation of this Warrant and, in
the case of any such loss, theft or destruction, upon delivery of an indemnity
agreement or bond satisfactory in form, substance and amount to the Company or,
in the case of any such mutilation, upon surrender and cancellation of this
Warrant, the Company at its expense will execute and deliver, in lieu thereof, a
new Warrant of like tenor.

     8. SURVIVAL. The various rights and obligations of the Holder hereof as set
forth herein shall survive the exercise and surrender of this Warrant.

     9. NOTICES. Whenever any notice, payment of any purchase price, or other
communication is required to be given or delivered under the terms of this
Warrant, it shall be in writing and delivered by hand delivery or United States
registered or certified mail, return receipt requested, postage prepaid, and
will be deemed to have been given or delivered on the date such notice, purchase
price or other communication is so delivered or posted, as the case may be; and,
if to the Company, it will be addressed to the address specified in Section 1
hereof, or such other address as the Company may specify by written notice given
hereunder, and if to the Holder, it will be addressed to the registered Holder
at his address as it appears on the books of the Company from time to time.

     10. AMENDMENTS. This Warrant may be amended or modified only by an
instrument in writing signed by the Holder and a duly authorized officer of the
Company.

     11. GOVERNING LAW. This Warrant shall be governed by, and construed in
accordance with, the laws of the State of Maryland (excluding choice of law
provisions thereof).

     IN WITNESS WHEREOF, AmericasBank Corp., has caused this Warrant to be
executed on its behalf under seal as of this 2nd day of September, 1998.

ATTEST:                                  AMERICASBANK CORP.


                                         By:                            (SEAL)
------------------------------               ---------------------------
Kenneth D. Pezzulla, Secretary               J. Clarence Jameson, III, President

<PAGE>

                                  PURCHASE FORM

TO: AMERICASBANK CORP.

     The undersigned hereby irrevocably elects to exercise the attached Warrant
to the extent of                 shares of the Common Stock, par value $0.01 per
                 ---------------
share, of AMERICASBANK CORP., and hereby makes payment of $                   in
                                                           ------------------
accordance with the provisions of Section l of the Warrant in payment of the
purchase price thereof.

                     INSTRUCTIONS FOR REGISTRATION OF STOCK
                      UPON THE STOCK LEDGER OF THE COMPANY

Name:
      ------------------------------------------
     (Please typewrite or print in block letters)

Address:
         ---------------------------------------

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                                                   Signature

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                                                   Name

                                                   -----------------------------
                                                   Date

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                                                   Social Security Number