MAZATLAN BIVALVES 69 



97. DiONE ? BBEVISPINOSA, SoiC. 



Cytherea brevispinosa, Soto. T/ies. Conch, p. 632, pi. 132, f. 109. 

 Dione brevispinata, Des/i. in B. M. Cat. Ven. p. 76, no. 70. 



Tablet 314 contains a minute valve wldch may be the young 

 of this species. It has close concentric rounded ribs, and very 

 strong teeth for the size. Length '03. 



jHaS. — Gulf of California, Col. Cuming.— ? Mazatlan, jun. 

 1 valve ; L'pool Col. 



98. DiONE CIECINATA, Bom. 



Venus circinata. Born, Test. Mus. p. 61, pi. 4, f. 9,.— Clemn. 



Conch. Cab. vi. 312, pi. 30, f. 2,ll.—Dillw. Sec. Sh. i. 169.— 



B. M. Cat. Sagr. Moll. p. 39, no. 474. 

 Cytherea circinata. Sow. Thes. Conch, p. 631, pi. 132, f. 104-6.— 



Forhes Sf^ Hani. Br. Mol. i. 399. 

 Dione circinata, Desh. B. M. Cat, Ven. p. 77, no. 72. 

 Venus Guineensis, Gmel. St/sf. Nat. p. 3270, &c. 

 Cytherea Guineensis, Lam. An. s. Vert. ed. Desh. vi. 311, &c. 

 Cytherea alternata, Brod. Proc. Zool. Sac. 1835, p. 45. 



Tablet 315 contains a small -white valve which may be the 

 young of this species : lonxj. "08, lat. '095, alt. "05. 

 -H"«5.— Cuba, Saffra.—S. Atlantic, Forbes.— ]\razatlan, Ca2}t. 



Donnel :— do. Lieut. Green, (Gould ms.) :— do. one valve and 



fragments, jim., L'2)ool Col.— Va.r. alternata, Monte Christi, 



in sandy mud, 11 fm., Cuming. 



99. DiONE CONCINNA, SoiV. 



Cytherea concinna, Proc. Zool. Soc. 1835, p. 2'i.—Soio. Thes. 



Conch, p. 630, pi. 132, f. 99, 100. 

 Dione concinna, Desh. B. M. Cat. Ven. p. 74. no. 61. 

 Comp. D. affinis, Brod. Proc. Zool. Soc. 1835, p. 45 ; B M. 



Cat. Ven. no. 60 : and D. tortuosa, Brod. id. ; B. M. Cat. 



Ven. no, 62. 



This shell is coloured in sienna brown and white stripes in 

 about equal proportions, the brown being darker on tlie ribs 

 and in the lunule. Umbos yellow. Concentric ribs occasionally 

 bifurcating. Pallial sinus, long, narrow, ascending. Lonq. 1-2, 

 lat. 1-56, alt. '75. 



B«J.— Panama, m fine sand, 10 fm. C«w /«</.— Mazatlan ; 1 sp. 

 with D. rosea ; L'pool Col. 

 Tablet 316 contains the specimen. 



