TLEXUOUS. 155 



their obliquity and the last being larger than the rest. Mr. 

 Eeeve's Monograph contains 16 species. East and West 

 Indies and Australia. P. trapezium. PI. xvii. fig. 386. 



FASTIGIELLA. Eeeve. Zool. Proc. 1851. A genus composed 

 of the single species figured, whose characters (as to the shell) 

 place it half way between Turritella and Cerithium. Ex. F. cari- 

 nata, Eeeve. PL xxviii. fig. 598, 



FAITNUS. Montf. Part of Melanopsis, Auct. 



FEEEUaiNEOUS. Of an iron rust colour. 



FEEUSSINA. G-rateloup. Stkophostoma, Deshayes. The latter 

 being the Latin name must be dropped, Ex. PI. xxv. fig, 

 534-5-6. 



riBEOTJS. A shell is said to be of a fibrous structure when a 

 fracture would present a series of perpendicular fibres, as Pinna. 



EICTJLA. Swainson, 1840. A generic group of shells, consisting 

 of those species of Pteula, Auct. which have the true pear- 

 shaped character. P. Eicus. PI. xvii. fig. 390. 



EIMBEIA. Megerle. Cobbis, Cuvier. 



EIMBEIATED, Eringed ; as Murex fimbriatus, a delicate white 

 species, with broad fringed varices. 



EISSTJEE, (Fissura, a sHt.) A slit or cut, a narrow perforation, 

 as in Emarginula and Eissurella. 



EISSUEELLA. Lamarck, 1801. (Fissura, a fissure.) Fam. 

 Caljrptracea, Lam, Branchifera, Bl, — Descr. Patelliform, oval 

 or oblong, radiated; apex anterior, perforated. — Obs. The Eis- 

 sureUge are known from Patellae by the perforation in the apex. 

 Eig. 245. The catalogue published by the author in the Concho- 

 logical Illustrations, enumerates 68 species. PI. xiii. fig. 245. 



EISTULANA, Lam. (i^z-s^wZa, a pipe.) Fam. Tubicolse, Lam. 

 Adesmacea, Bl. — Descr. A transversely elongated, equivalve, in- 

 equilateral bivalve, enclosed by a septum within the widest, 

 closed extremity of a straight calcareous tube. Eistulana is 

 known from Gastrochaena by the straightness of the tubes, and 

 the oblong state of the valves. Eistulana Clava. PI. ii. fig. 53, 54. 



ELEXUOTJS. Having windings or bendings. Ex. The TeUinae 

 are known by the twist or flexuosity in the posterior ventral 

 margin of the shell. 



