718 MR. E. A. SMITH ON SHELLS FROM LAKE NYASSA. [NoV. 6, 



Length 10 millims. ; diam., with aperture, 8i ; length of aper- 

 ture 9, diam. 4. 



Hab. Lake Nyassa. 



This species is remarkable on account of its solidity, the short 

 subtriangular form, and the small spire, which rises but very little 

 above the rounded angle or shoulder of the last whorl. 



The columella is nearly perpendicular, with a slight sinuosity 

 inferiorly. 



18. Physa succinoides, sp. nov. (Plate LXXV. figs. 19, 20.) 

 Shell small, ovate, moderately solid, imperforate, pale greyish 



brown ; whorls three, convex ; suture deep ; spire very small, 

 scarcely exserted above the body-whorl ; the latter very large, rather 

 strongly striated by the oblique lines of growth ; aperture ovately 

 auriform, occupying about ^j of the entire length of the shell ; 

 columella oblique, sinuated in the middle. 



Length 5| millims. ; diam., with aperture, 4. 



Hah. Lake Nyassa. 



This little species is peculiar in its form, which reminds one of a 

 small sinistral Succinea. The shortness of the spire, and the few- 

 ness of the volutions are the most prominent features. 



19. Physopsis africana, Krauss. 



Physopsis africaua, Krauss, Siidafrik. Moll. p. 85, pi. v. f. 14 ; 

 Kiister, Conch. Cab. p. 72, pi. 12. f. 29,30; Adams, Gen. Rec. 

 Moll. iii. pi. 83. f. 10. 



Physa africana, Krauss, Sowerby, Con. Icon. xix. pi. 1. f. 2a-b. 



Hab. Port Natal {Krauss). Lake Nyassa {Kirk), teste Dohrn, 

 P. Z.S. 1865, p. 233. 



20. Limn^a natalensis, Krauss. 



LimncBa natalensis, Krauss, Siidafrik. Moll. p. 85, pi. v. f. 15 ; 

 Kuster's Con. Cat., No. 42, pi. 6, f. 1, 2,3; Sowerby, Conch, Icon, 

 xviii. pi. 7, f. A&a-b. 



Hab. Natal {Krauss). Lake Nyassa {Kirk). Dohrn, I. c. 



21. Cy'rena ASTARTiNA, Martens. 



Cyrena astartina. Martens, Malak. Blatt. vi. (1859) p. 219, pi. 3. 

 f. 6, 7 ; Prime, Cat. Corbiculidse, American Journ. Conchol. v. no. 7 

 (Corbicula) ; Dohrn, P. Z. S. 1805, p. 234. 



Hab. Tette, Zambezi River {Martens) ; Lake Nyassa {Dohrn 

 and Prime). 



22. Cyrena (Corbicula) radiata, Parreyss. 



Cyrena radiata, Parr. Philippi, Abbild. ii. p. 4, pi. i. f. 8. 



C. africana, Krauss, part, Siidafrik. Moll. p. 8. 



Three specimens of this Nilotic species were obtained by Mr. 

 Simons in the Lake. One of them is rather more inequilateral 

 than normal examples, having the posterior end somewhat the 

 longer. The concentric sulcation, too, in all three shells, is a little 

 finer, and the violet rays somewhat obscure. 



