Question: What body part is located ant the anterior end and what part is located at the base of the tail?
About the article "Anatomy", section "Vertebrate anatomy".

Candidate passages:
The body of pancreas is the largest part of the pancreas and located between the neck and tail of the pancreas.
The body of pancreas is located at the same level as the transpyloric plane.
The body of pancreas is somewhat prismatic in shape, and has three surfaces: anterior, posterior, and inferior. 
The genus Xidazoon was erected by Shu, et al.
(1999) based on fossils found in the Qiongzhusi (Chiungchussu) Formation, Yu'anshan Member (Eoredlichia zone), Lower Cambrian, Haikou, (Kunming), about 50 km west of Chengjiang, China.
It currently consists of the single species "Xidazoon stephanus".
The fossils show that the body of the animal was divided into two parts.
The anterior part of the body is moderately inflated, with a prominent mouth circlet.
It has faint transverse divisions towards the front, but is otherwise smooth.
The mouth circlet consists of about 30 plates divided into inner and outer regions.
The anterior section has five structures on each side, which are interpreted as gills.
A dark region running close to the ventral and posterior margins is interpreted as an endostyle.
The condition of the anterior portion of the fossils suggests that it was thin-walled, i.e., that the anterior portion was largely hollow.
The posterior part of the body tapers towards front and back (diamond-shaped), and is divided into seven segments covered in cuticle with three less well-defined segments at the anterior end.
There are short spines at the posterior tip.
The authors describe an alimentary canal with terminal openings and a rectum with what might be dilator muscles.
Based on a comparison of the incomplete/damaged holotype with the incomplete/damaged holotype of "Pomatrum ventralis", researchers Aldridge, et al., proposed that "X. stephanus" was a junior synonym of "P. ventralis" because the anterior portions of the two species are largely identical.
However, other researchers point out that, although the anterior portions may be extremely similar, the posterior portions of the carapaces differ in shape and width, and, more importantly, the tails differ greatly, in that in "X. stephanus", it is composed of seven segments and leaf- or diamond-shaped, while in "P. ventralis", the tail is oar-shaped, and is composed of many more segments, especially near its base. 
Its body is spirally coiled and darkly coloured (due to eel blood inside the nematode's intestine).
It is fusiform, tapering to both ends; anterior end of the body is bottle-shaped, while the posterior end is narrowed and conical.
The epicuticle is finely wrinkled, with a network structure, forming an irregular fine transparent coating.
The cuticle of the anterior andposterior parts of its body bear several papilla-like excrescences of a fibrous structured.
Its head end is rounded, being separated by a slight constriction in front of the nerve ring.
The entire anterior narrowed part of its body is approximately twice as long as the oesophagus.
Four dorso- and ventro-lateral papillae and two small lateral amphids are present.
The mouth is conspicuously depressed, the anterior margin of the buccal ca.psule being 0.027mm-0.030mm from the anterior extremity; the mouth opening is circular.
The buccal capsule is well sclerotised, trapezium-shaped in lateral view, its anterior rim bearing one row of 26 circular teeth.
Its oesophagus is strongly muscular and expanded at its posterior half, its lumen being triangular.
The valvular apparatus of the oesophagus is well developed.
The excretory pore is located near the junction of the oesophagus and intestine.
The intestine is dark, almost straight, broad, being narrowed at its anterior and posterior ends only.
Three conspicuously large oval unicellular rectal glands are present, one dorsal and two subventral.
The tail is conical and short.
The length of the male body is ; in females it ranges between . 
Together with the putamen, the caudate forms the dorsal striatum.
The dorsal striatum is considered a single functional structure, yet because it is separated by a large white matter tract –– the internal capsule –– it is often referred to as two structures, the medial dorsal striatum (the caudate) and the lateral dorsal striatum (the putamen).
In this vein, the two are functionally distinct not as a result of structural differences, but merely due to the topographical distribution of function.
The caudate nuclei are located near the center of the brain, sitting astride the thalamus.
There is a caudate nucleus within each hemisphere of the brain.
Individually, they resemble a C-shape structure with a wider "head" ("caput" in Latin) at the front, tapering to a "body" ("corpus") and a "tail" ("cauda").
Sometimes a part of the caudate nucleus is referred to as the "knee" ("genu").
The head and body of the caudate nucleus form part of the floor of the anterior horn of the lateral ventricle.
After the body travels briefly towards the back of the head, the tail curves back toward the anterior, forming the roof of the inferior horn of the lateral ventricle.
This means that a coronal (on a plane parallel to the face) section that cuts through the tail will also cross the body and head of the caudate nucleus. 
Dark brown dorsally and ventrally.
Sides with vertical yellow spots or a wavy or zigzag stripe on the anterior half of the body.
A yellow ring around the base of the tail.
Adults may attain a total length of 37 cm (14½ inches).
Dorsal scales in 17 rows at midbody (in 19 rows behind the head).
Ventrals 148-162; subcaudals 4-7.
Snout acutely pointed.
Eye in the ocular shield.
No supraoculars.
No temporals.
Frontal longer than broad.
No mental groove.
Diameter of body 22 to 32 times in the total length.
Ventrals only slightly larger than the contiguous scales.
Tail ending in a large convex rugose shield, which is neither truncated nor spinose at the end.
Caudal disc 1/2 to 3/5 the length of the shielded part of the head.
Some of the distal dorsal scales of the tail weakly keeled.