262 F. Stoliczka — On the Gyclostomacea of Fencing. [No. 3, 



Group.— GYGLOSTOMAGJEA. 



Fam. Cyclophobidje. Genus, Cyclophoktts, Montf. 

 Cyclophoeus Malayanus. PI. X, Figs. 1-5. 



Benson, A. and M. N. H., 2nd ser., vol. x, p. 269. Pfeiffer, Monograph Pneumo- 

 nopomorum. Snppl. I, p. 42. Reeve, Conch, vol. xiii, Gyclophorus, pi. I, fig. 2. 



This is a tolerably common species on Penang, being generally distri- 

 buted from near the seashore to the top of Penang hill, about 2500 feet. 



I have given a whole series of illustrations in order to shew the diffe- 

 rent stages of growth, although Reeve's figure is a very good representation 

 of an adult specimen. 



Ordinarily the shell is smooth, exhibiting only the usual finer and 

 stronger stria? of growth, but the pale brown and thin cuticle when well 

 preserved is spirally striated, the striation being more conspicuous in young- 

 er shells than in more adult ones. 



Young specimens of only two or three volutions have very conspicuous 

 transversely oblicpie cuticular striae, and in this stage the shell with its 

 angular last whorl perfectly resembles Pfeiffer's Cyclostoma (Leptopoma) 

 Binnanum,* which is no doubt either a young of the present species or of 

 C. Siamensis. Nearly all young Gyclophori have these transverse filiform 

 striae of the cuticle. 



When larger the shell scarcely differs from that of O. Cantori, Benson, 

 of which figures are given by Pfeiffer in Chemnitz' Conch. -kab., and also by 

 Reeve. I have not obtained in Penang any such small specimens with fully 

 developed lips as are represented in those figures, but I have observed that the 

 usual difference of the male being often slightly smaller than the female 

 also exists in the present species, and an illustration of a nearly full 

 grown male, given in fig. 4>, comes very close to that of Reeve. Judging 

 from the difference observed in the size of the sexes of other species, 

 as is for instance very often the case in G. Fearsoni, I am inclined 

 to the opinion that the specimens described as G. Gantori are males 

 of G Malayanus, the latter being females. If this were the case, the 

 former name would have priority over the latter, but even if the expla- 

 nation of sexes would not in this case hold good, I believe that the form 

 described as Gantori can scarcely be looked upon as anything else than a 

 smaller race of Malayanus, and vice versa. 



The animal is grey, darker on the head, brownish on the tentacles, pale 

 towards the tip of the rostrum and at the basal edges of the foot. 



* Chemnitz' Concliylienkabinet, Vol. IX, p. 363. andMon. Pneum. Snppl. II, p 85. 



