140 MAZATLAN BIVALVES 



191. BYSSOABCA FCJSCA, Brug. 



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



f. ~R,.Encycl. pi. 308, f. &. Dillw. Cat. vol. i. p. 231, 



no. 14. Lam. An. s. Vert. vol. vi. p. 466, no. 14. five. 



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

 Area barbata, var. G-mel. p. 3307. ScJirot. Einl. vol. iii. p. 279, 



no. 2 List. Conch, pi. 231, f. ffi.G-ualt. 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. 



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



The presence of this well-known East Indian shell in the 

 Mazatlan fauna is very suspicious. 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 Gulf seas ; or these specimens 

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

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

 an entrance into their appropriate box by an accident of the 

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

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

 1'24, lat. 1'98, alt. '97. 

 Sab. Madagascar and Barbadoes, Lamarck. "Singapore," 



abundant, P. P. C. Barbadoes, (young valves) IP. P. C. 



Cuba, Sagra. Mazatlan : extremely rare ; L'pool Col. 



Tablet 650 contains the specimen I found. 



192. BYSSOABCA VESPEETILIO, n. s. 



B. t. oblongd, compressd, postice tumidiore, expansa ; valde 

 incequilaterali, marginibus subrotundatis, hiatu pedis modico, 

 margine ibi incurvo ; umbonibus subappressis, ligamento Iongo 9 

 angusto, antice brevi ; superjicie radiatim striatd, <striis sub- 

 impressis, lineis incrementi vix decussatis ; rubro- 

 fuscd, intus maculis duabus ab uinbonibus radiantibus ; epider- 

 mide lamellis concentricis, antice squamosis, postice brevibus ; 

 setis interstitia decurrentibus, in lamellis imbutis ; hue 

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

 ubi semitubulares sunt ; dentibus haud parvis, hand 

 numerosis, lineis valde incurvatis, anticd brevi. 

 Compare A. setigera, Rve. Proc. Zool. Soc. 1844, p. 124 ; Conch. 



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



