142 MAZATLAN BIVALVES 



Hani. Boscr. Cat. p. 155, pi. 18, f. 39.— i?. IL Cat. B'Orh. 

 Moll. p. 81, no. 725.— C B. Ad. Pan. Shells, p. 258, no. 41G, 

 = (Teste Krauss, Sudafr. Moll. p. 16) Area squamosa, Lam. 

 An. s. Vert. vi. p. 474., no. 35. — Hani. Bescr. Cat. p. 158. — 

 = (teste Besh.) Area Domingensis, Lam. A. s. V. vi. p. 407, 

 no. 16. (cliflFeriug in colour.) — = (teste Besh.) Area clatkrata, 

 Befr. A. s. V. vi. p. 478, no. 6, (fossU.) 

 Compare Byssoarca divaricata Sow. Proc. Zool. Soc. 1833, 

 p. 18 : — (Area d.) Pvc. Conch. Ic. pi. 16. f. 108. (Annaa or 

 Chain Is. attacked to stones, Cuming ; W. Indies, B. M.) 

 Comp. Bvssoarea pusilla. Soii\ Proc. Zool. Soc. 1833. p. 18 — 

 (Arcap'.) B. M. Cat. BOrh. Moll. p. 81, no. 717. (Iquiqui, 

 Peru, on stones at low water, Cuming ; Bolivia, Cobija, 

 Peru, Arica, B'Orhigin/.) 

 Comi). Area douaeiformis, Itvc. Conch. Ic. pi. 16, f. 104 : — 

 Proc. Zool. Soc. 1844, -p. 125, (Mozambique Channel, in 

 Madrepore, Hanlccy.) 



This species varies considerably in the fineness or coarseness 

 of the cancellated markings, in the projection or otherwise of 

 the posterior rib, and in the shape, which often approximates 

 B. solida, and is not unfrequently greatly appressed. Liga- 

 ment ver\' narrow, solid, only adlieriiig at the posterior part, 

 whence it makes a slight turn round the umlios, as in B. illota. 

 Hinge teeth rather few, slanting, on unequal lines slightly 

 diverging. ^luscidar scars ]jrominent, glossy white, as though 

 on a single plate attached to the shell. The pedal diink is 

 perceptible, but very small. These characters include speci- 

 mens from the W. Indies, which are undoubtedly A. squamosa, 

 Lam. also quoted by Krauss from !Xatal. If, as is probable, 

 the species are identical, the Lamarckian name has priority'. 

 Another "W. Indian species, probably A. umbonata, A. s. v. 

 p. 462, no. 5., differs in the fineness of the cancellations, and in 

 the ligament which fills a central pit, as in B. solida. The 

 A. pusilla of D'Orb. may be a dwarf var. of the !Mazatlan sheU, 

 but the Cumingian type appears distinct. A specimen of the 

 tj-pical form measures long. '4,7, lat. "83, alt. "38. 

 Huh. — Mazatlan, Bccchci/'s Yoi/agc : — Do. rare, nestling in 

 crevices of large shells ; Bpool Col. — Sta. Elena, attached 

 to stones, Cuming. — Ecuador, Sta. Elena, BOi'higny. — Sta. 

 Barbara, Col. Jewitt. — Taboga ; iinder stones near low water 

 mark, very rare ; C. B. Adani.f. — Also given from Ld. Hood's 

 Is. and the Marquesas. — (A. squamosa.) "x^. HoUande, a 

 I'ile King. Mus." Lamarck. — JNatal, Krauss. — (A. Domin- 



