30 LAND AND FRESHWATER 



The animal is very pale ochre-coloured, with a short, broadly 

 oval, divided foot (PI. LXVII. figs. 1, 1 a) ; the muzzle is transversely 

 striated. The penis (figs. 2, 2 a) is large, broadly thickened, and 

 tongue-like, diminishing rapidly at the free end into a sharp point ; 

 the seminal duct appears to run down the side of the muscular sheath 

 (fig. 2 h), and the seminal orifice (F.aj).) is situated on the flat un- 

 derside, a very short distance from the pointed end. The rectum is 

 situated immediately to the riglit, and runs as a tube attached to the 

 side of the branchial chamber for some distance, and then has a 

 short free end at the anal orifice (fig. 2 a, Au.or.). In the female 

 (fig. 3) the rectum is not so long, and the female orifice (f.or.) 

 is just above it. 



The centre tooth of the radula (fig. 4) is straight-sided, gradually 

 narrowing from the base, elongate, bearing five minute cusps on a 

 slightly curved edge. The first side-tooth (fig. 4 a) is very long, 

 gradually widening from the base, and curving over and inwards at 

 the cutting-edge, with about six or more small teeth. The second and 

 third (fig. 4 5) are almost similar in form, narrowly elongate, sides 

 parallel, with eight or ten minute serrations like the blunted teeth 

 of a saw. On the underside of the buccal mass (fig. 5 a) a congeries 

 of fine convoluted tubes was seen, representing the salivary glands. 



OtOPOMA CLATHRATULrM, liccluz. 



Cyclostoma clatliratulum, Recluz, Rev. Zool. Cuv. p. 3 (1843), et 

 Mag, Zool. pi. Ixxiv. (1843). Socotra. 



Cyclostoma clathratulum. Sowerby, is from Arabia. 



Original description : — " Long. 22, lajg. du dernier tour 23|, 

 hauteur de la spire 11^ mm. 



" Cette espece me parait jeune ; ses rapports avec le jeune du 

 C. naticoides me font croire qu'elle n'est (ju'une variete de coloration 

 de la meme espece ; cependant les nombreux individus rapportes 

 par M. le Commandant Jehenne sont tons colorcs et sculptes 

 de la meme maniere, et ont le peristome aigu et tranchant." 



A spirit-specimen of Otopoma clatliratulum, var. minor, G.-A. 

 (PL LXVII. fig. 6), the shell of which was described by me in the 

 P. Z. S. 1881, p. 255, was also examined. The male organ is in the 

 same position, but has a more elongated form (fig. 6) and of the 

 same diameter throughout. The radula is precisely like that of 

 0. naticoides. 



In the description of Cyclostoma eleejans by the Eev. M. J. 

 Berkeley, 'Zoological Journal,' vol. iv. 1828-29, the penis is 

 described as " a flat, ligulate, transversely wrinked, pointed process, 

 lying, when at rest, parallel to the rectum, and folded in the middle 

 on itself." This agrees closely with that of Otopoma, and shows 

 this to be in form and the position a common character of the 

 Cyclostomida). 



There were no spirit-specimens of any operculatcd land-shells 

 from either South Africa or the Mauritius in the Natural History 

 Museum with which I could compare this Socotran genus, and but 

 one from Madagascar, viz. a T'ropidopliora. By the kindness of 



