24 LAND AND FRESHWATER 



Animal with a long foot extending far bej'ond the operciilum. 

 Operculum indistinctly spiral, smooth in front, flat, thin ; at back 

 with a very large raised boss, fitting into a circular pit in the foot. 

 Male generative organ as in Cyclophorus aurora, pearsoni, &c., as 

 also the teeth of the radula. 



Shell very solid and turbinate. 



Its closest relationship is therefore with the Indian and Malayan 

 forms. 



Cyclophorps (Cyclouelix) crocatus, Born. (Plate LXVIII. 

 figs. 5-8.) 



Turbo crocatus. Bom, Index, p. 345 (1778). 



Trochus crocatus, Born, Test. p. 338, t. sii. figs. 11, 12 (1780). 



Var. turbo : 



Helix turbo, Chemnitz, Conch. -Cab. ix. fig. 1059. 



Cyclostoma maciilo^a^ Jag. Cat. 1839, p. 121, t. vii. figs. 9, 10. 



Cyclostoma turbo, Rowerby, Thes. p. 116. no. 75. figs. 102, 103, 

 from Nieobar (collection Spengler). Mfireh says specimens often 

 differ slightly. In Journ. Conch. 1876, p. 360, Morch says Spengler's 

 examples measure 24 mm. in diameter. 



Cyclostoma {CyclohelLv) crocatus. Born ; Morch, Journ. de Conch, 

 p. 316 (1872). 



Cyclohelix crocatus. Nevill, Hand-list, p. 274 (1878) : Camorta. 



Cyclophoms turbo. Reeve, Conch. Icon. pi. xiii. fig. 57. 



The animal (figs. 5, 5 «.) (from spirit-specimen) is like that of 

 the Indian species C. aurora, 2^c(frso7ii, &c. — the male organ (P.) 

 being situated close below the right eye and right tentacula (t.), 

 rather short and pointed. The foot is much longer (fig. 5 /*). On 

 the operculum being removed a deep circular pit is seen near the 

 left central margin of the oval scar and into which the well- 

 developed boss on the inside of the operculum fits. 



The radula (fig. 7) is folded back on itself at the posterior end, 

 where a retractor muscle (r.m.) is given off". It is enveloped by 

 two equal-sized salivary glands. The buccal mass is bilobed and 

 globular in shape. The buccal plates are about 3 mm. long on the 

 central line, 6 mm. wide, and with fine tessellated surfaces. 



The central tooth (fig. 8) is broad, with 5 cusps on the cutting- 

 edge ; it then narrows rapidly into a waist-like form, and expands 

 again below to the bottom line of the lower plate. The first side- 

 tooth is long and narrow, tricuspid, and the two next are smaller 

 and indistinctly tricuspid. 



The claim of this species for subgeneric rank is therefore not 

 confined to the shell, but is borne out by other details of the 

 animal. 



The turbinate shell, C. herlcJotsi, v. Mart., from Japan (Die 

 Preu'^s. Exped. Ost-Asien, p. 13), is represented as having a well- 

 developed boss on the inside of the operculum (see pi. iii. fig. 1), 

 but it does not stand out so conspicuously as in C. crocatus. 



