Neopyrgoma Ross & Newman 2002, n. gen.
Creators: name: Ross, A.
name: Newman, William A.
Publisher: name: Zenodo
Year: 2002
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Maxillopoda
Sessilia
Pyrgomatidae
Neopyrgoma

description: Neopyrgoma n. gen.   
 De®nition. Wall single-plated, solid, low conical, not ribbed, margin deeply lobate; basis with arch-like calcareous structures alternating between solid, longitudinal, medially sulcate ribs, terminating between and below marginal lobes of wall.   
 Type species. Pyrgoma lobata Gray, 1825, designated herein.   
 Etymology. Derived from the Greek, neo- new, and - Pyrgoma, little tower, in allusion to its derived structure and aYnities. The gender is neuter.   
 Remarks. Gray (1825: 102) brie¯y described the wall as`Shell concentrically striated, deeply lobed’ which he diVerentiated from P. cancellatum in having a`... shell radiately ribbed’. His description of the operculum is`... conical, four valved, ventral valve [= scutum] linear, posterior valves [= terga] hooked narrow triangular’.   
 The deeply lobed wall, best described as a torus suspended by ¯ying buttresses, clearly distinguishes this genus from Pyrgoma. The distinction may seem trivial, but in reality it represents a radical innovation that entails considerable modi®cation in growth of the wall and basis. Darwin (1854) did not recognize the arch-like structures forming a considerable part of the basis in Pyrgoma, and therefore he did not appreciate the signi®cance of the deeply lobed margin of the wall in this species. He was also likely misled by his observation that juvenile specimens of P. cancellatum have a wall with the ribs extending beyond the periphery (a characteristic found in essentially all coral-inhabiting barnacles having a ribbed wall).   
 Neopyrgoma lobata (Gray, 1825) (®gure 4) P. [yrgoma] lobata Gray, 1825: 102.   
 [Pyrgoma] lobata: Darwin, 1854: 362, in part, pl. 12, ®gure 5a.   
 Creusia rayonnant e Blainville, 1827, pl. 116, ®gure 7a, b.   
 Diagnosis. Because there is only a single incomplete specimen the diagnosis is the same as for the genus.   
 Type locality and host. Locality unknown, host not identi®ed.   
 Type depository. Holotype, Natural History Museum, London, no. 1998.2837.   
 Remarks. Gray (1825) described brie¯y the wall and operular plates, based on a single specimen (rostro-carinal diameter 10.3 mm), but the opercular plates are not glued to the slab and apparently have been lost. There is a small hole between the wall and basis at the rostral end, through which the opercular plates were evidently removed. Glued to the reverse side of the slab there is a small slip of paper which, in Darwin’s cursive handwriting, reads` P. lobata P. cancellatum’.   
 We are unable to interpret Gray’s description of the opercular plates. However, it would appear they were somewhat diVerent from those of P. cancellatum. The apical portion of the wall is suVused with rose-pink and the growth ridges are nodose. None of the species of Pyrgoma are known to have a pigmented wall.   
 After completing our manuscript we had the opportunity to examine a photograph of what is likely this or a related species. The intact wall of this specimen, on Tubastrea micranthus, was collected from Sumilon Island in the Philippine Archipelago (Schuhmacher, in litt.). Inasmuch as Gray (1825) did not cite a locality or host for his species, it is informative to note the presence of Neopyrgoma in the Philippines.
description: Published as part of Ross, A. & Newman, William A., 2002, A review of the Pyrgoma cancellatum species complex (Cirripedia: Pyrgomatidae), pp. 407-421 in Journal of Natural History 36 (4) on pages 416-417