140 • MAZATLAN BIVALVES 



191. Byssoaeca fcjsca, Brmj. 



Area fiisca, Brug. Diet. no. 10. — D'Avila, Cat. vol. i. pi. 7, 

 f. 'R.—Enci/cl. pi. 308, f. o. — Bilbo. Cat. vol. i. p. 231, 

 no. 14. — La)?t. An. s. Vert. vol. vi. p. 466, no. 11. — Rve. 

 Conch. Ic. pi. 12, f. 82.-5. M. Cat. Cuba Moll. p. 43, no. 523. 



Area barbata, var. Gmel. p. 3307. — Schrot. Einl. vol. iii. p. 279, 

 no. 2.— List. Conch, pi. 231, f. Qo.— Gualt. Test. pi. 90, f. B.— 

 Chemn. Conch, vol. vii. pi. 54, f. 534. 



Area bicolorata, Chemn. Conch, vol. xi. p. 243, pi. 204, f. 2007.— 

 Billw. Cat. vol. i. p. 230, no. 11. 



Tke presence of this well-known East Indian shell in tbe 

 Mazatlau fauna is very suspicions. I took one fresh pair, and 

 Mr. Darbishire another, out of the Byssoarca box, when I first 

 examined the Collection. As it is said to reach the West In- 

 dies, it may linger also in the Gidf seas ; or these specunens 

 may have come over on ship bottoms or drifting timber, or in 

 ballast ; or they may, in some unaccounted way, have found 

 an enti'ance into their appropriate box by an accident of the 

 owner's. A small oyster attached is not distinguishable from 

 the Mazatlau species ; but this does not prove much. Long. 

 1-24, Za^. 1-98. alt. -97. 



Sah. — Madagascar and Barbadoes, Lamarck. — "Singapore," 

 abundant, P. P. C. — Barbadoes, (young valves) \B. P. C. — 

 Cuba, Sarjra. — Mazatlau : extremely rare ; L'pool Col. 



Tablet 650 contains the specimen I found. 



192. Byssoaeca vespeetilio, n. s. 



B. t. oblongd, compressa, postice tuinidiore, expansA ; valde 

 incBqidlatevali, maryinihus suhrotundatis, hiatti pedis modico, 

 margine ibi incurvo ; umhonilms subappressis, ligamento longo, 

 angusto, antice brcvi ; superjicic radiatim striata, striis suh- 

 impressis, lineis incrementi vix de cuss at is; rubro- 

 fuscd, intus maculis dtiabiis ab iimbonibus radiantibus ; epider- 

 mide lamelUs concentricis, antice squaniosis, postice brevibios ; 

 setis inter.'ititia decurrentibi(,s; in I a nielli s i mbutis ; hue 

 et illuc lineis setarum validis, longis, maxime latere postico, 

 uhi semitubulares stmt ; dentibus hand parvis, hand 

 numerosis, lineis valde incurvatis, anticd brevi. 

 Compare A. setigera, Rve. Proc Zool. Soc. 1841, p. 121 ; Conch. 



Ic. pi. 14, f. 94. (Zanzibar, under stones at low water, Thorn.) 



