OCR Text |
Show 718 MR. E. A. SMITH ON SHELLS FROM LAKE NYASSA. [Nov. 6, Length 10 millims.; diam., with aperture, 8£ ; length of aperture 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. P H Y S A SUCCINOIDES, sp. nov. (Plate L X X V . 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 T\ of the entire length of the shell ; columella oblique, sinuated in the middle. Length 5| millims.; diam., with aperture, 4. Hab. 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 fewness of the volutions are the most prominent features. 19. PHYSOPSIS AFRICANA, Krauss. Physopsis africaua, Krauss, Siidafrik. Moll. p. 85, pl. v. f. 14 ; Kiister, Conch. Cab. p. 72, pl. 12. f. 29,30; Adams, Gen. Rec. Moll. iii. pl. 83. f. 10. Physa africana, Krauss, Sowerby, Con. Icon. xix. pl. 1. f. 2a-b. Hab. Port Natal (Krauss). Lake Nyassa (Kirk), teste Dohrn, P. Z. S. 1865, p. 233. 20. LIMN,EA NATALENSIS, Krauss. Limncea natalensis, Krauss, Siidafrik. Moll. p. 85, pl. v. f. 15 Kuster's Con. Cat., No. 42, pl. 6, f. 1,2,3; Sowerby, Conch. Icon. xviii. pl. 7, f. 46a-b. Hab. Natal (Krauss). Lake Nyassa (Kirk). Dohrn, /. c. 21. CYRENA ASTARTINA, Martens. Cyrena astartina, Martens, Malak. Bliitt. vi. (1859) p. 219, pl. f. 6, 7 ; Prime, Cat. Corbiculidae, American Journ. Conchol. v. no. 7 (Corbicula) ; Dohrn, P. Z. S. 1865, p. 234. Hab. Tette, Zambezi River (Martens) ; Lake Nyassa (Dohrn and Prime). 22. CYRENA (CORUICULA) RADIATA, Parreyss. Cyrena radiata, Parr. Philippi, Abbild. ii. p. 4, pl. 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. |