24 CXCIiOPHOBlDiE. 



It differs from that, of Cydophorus in the form of the lateral 

 teeth, and in their denticulatioiis heing shorter and more numerous. 

 In C. {Ditropts) convexus. the species examined, the central tooth 

 has 7 denticulations, that in the middle being the largest ; all the 

 lateral teeth apparently had 5 denticulations, but it appeared vei-y 

 difficult to count those in the outermost laterals correctly. 



36. Ditropis Ijeddomei, Blanfonl. 



Cydophorus {Ditropis) heddomei, Blaufurd, J. A. 6. B. xxxviii,part 2, 

 1869, p. 127, pi. 16, fig. 2 ; N«vill, Hand List, i, 1878, p. 278. 



Ditropis heddomei, Ilanley & Theobald, Conch. Ind. 1875, pi. 136, 

 tigs. 8, 9 ; Theobald, Cat. Shells Brit. India, 1876, p. 37 ; Ivobelt 

 & Molleudoiff, Nachr. Ueuts. Malak. Ges. xxix, 1897, p. 86; id.. 

 Cat. Pneum. 1899, p. 14. 



Ditropis (Ditropis) heddomei, Kobelt, Das Tierreich, Lief. 16, 1902, 

 p. 72. 



Original description: — '-Testa latissime umbilicata, depressa, 

 discoidea, tenuis, olivacea, confertissime striata, paruiu nitida,spira- 

 liter costata. Spira plana, sutura valde impressa. Anfr. circa 4, 

 (prime in exempio unico deiicienti) convexi, primi fere glabri ; 

 peuultimus costis 2 8, supra uni, infra in umbilico, juxta suturam 

 ornatus, ultimus antice descendens, teres, juxta suturam et subter 

 peripheiiam glaber, 7-costatus, costis 4 superioribus, quarum 

 extera ad peripheriam, 3 basalibus ab superis intervallo dityunctis. 

 Umbilicus perspectivus. Apertura diagonalis, rotunda ; peristoma 

 simplex, rectum, breviter adnatum, nigrescens, intus tenuiter 

 albido-labiatum. Operculum fusco-corneum, intus convexum, 

 limbo tenuissimo circumdatum, extus coucaviusculum, marginibus 

 anfractuum parum elevatis. 



"Diam. maj. 8, min. 6f, axis 2\ millem., ap. diam. intus 2. 

 " Shell very widely umbilieated, depressed, discoidal, thin, 

 olive-coloured, very closely and minutely striated, less polished 

 than the other species, and covered with spiral ribbing. The spire 

 is flat, or nearly so, but the innermost whorls being deficient in the 

 only specimen sent for description by Major Eeddome, it is im- 

 possible to say whether the apex is slightly exserted or not. The 

 suture is much impressed, Whorls about 4 in number, convex ; 

 the last one descending near the mouth, smooth near the suture, 

 both above and below, with 7 spiral ribs ; 4 above, the outermost 

 forming the perijdiery of the shell, and 3 below, separated from the 

 others by a smooth space; 3 of the upper and 1 of the lower can 

 be traced on the penultimate whorl near the suture, but become 

 obsolete on the inner whorls. The umbilicus exposes all the 

 whorls below. Aperture diagonal, round, peristome only joined 

 for a verv short distance to the penultimate whorl, thickened, all 

 in one plane and not expanded, faintly edged with white inside, 

 blackish externally. 



"The operculum diii'ers from that of Cyclop)horus pjlanorhis by 

 the edges of the whorls being less pi-oduced externally, and by its 



