360 BALANID.E. 



as it would appear, in the East Indian Archipelago. From 

 the habits of the corals, most of the species must be inha- 

 bitants of shallow water. Pyrgoma Anglicum, however, is 

 an inhabitant of deep water on the southern shores of Eng- 

 land, whereas at St. Jago, in the Cape cle Verde Islands, I 

 myself collected it adhering to a Caryophyllia, within the 

 tidal limits. This same species existed on the shores of 

 England during the Coralline Crag period ; and at this epoch 

 it attained a larger size than at present. Two species of the 

 genus, according to Sismonda, are found in the tertiary beds 

 of Piedmont. Mr. Stutchbury, who is so well acquainted 

 with recent cirripedes, informs me that he has for many 

 years examined fossil Secondary corals, in the expectation of 

 finding imbedded, species of this genus or of some allied 

 form, but without success. The same species of Pyrgonm 

 is by no means always confined to the same coral : I have 

 seen P. crenatum on four or five different corals, and P, 

 Anglicum on at least three kinds : on the other hand, I have 

 seen P. millepora? only on the Millepora complanata (a 

 member, as I believe, of the vegetable kingdom), and P. mon- 

 ticularia? on a Monticularia from near Singapore. 



1. Pyrgoma Anglicum. PI. 12, fig. 4# — 4 e. 



Pyhgoma Axglica. G. B. Sowerby. (sine descript.) Genera of 



Recent and Fossil Shells, fig. 7, No. 18, 

 Sept. 1823. 

 Megatrema (Adna) Anglica. J.E.Gray. Annals of Philosoph. 



(new series), vol. x, Aug. 1S25. 

 Pyrgoma sulcatum. Philippi. Enumcratio Molluscorum Sicilise, 



Tab. 12, fig. 21, (1836). 

 — anglica. Brown. Illustrations of Conchology, (2d edit., 



1844), Tab. 53, fig. 27—29. 



Shell steeply conical, purplish red: orifice oval, narrow ; 

 basis permeated by pores, generally exserted out of the coral : 

 scutum and tergum sub-triangular. 



Huh.— South coast of England and of Ireland, (12 to 45 fathoms, Forbes 

 and MacAndrew) ; Sicily ; Madeira; St. Jago, Cape de Verde Islands ; generally 



