264 F. Stoliczka — On the Cyclostomacea of Fencing. [No. 3, 



authentic, being taken from the type in Benson's collection, I would not 

 hesitate to %A& porphyriticus as a synonym of Borneensis. Sowerby's original 

 figures o£ perdix (at least fig. 127 in Thes. vol. I) and ofaquila scarcely differ, 

 and both very well agree with the form of Borneensis as usually obtained at 

 Singapore, having the whorls above rather inflated and the periphery very ob- 

 tusely angular. The same applies to Chemnitz's figure of aquila, while 

 that of perdix, after Tenaserim specimens, very closely corresponds with 

 one of my Penang specimens of Borneensis, except in having a greenish 

 cuticle. Reeve's figure of aqiiila is probably taken from a specimen obtained 

 inland north of Singapore ; those specimens are particularly fine and pro- 

 bably most aberrant from the type shell, which Reeve figured as Borneensis, 

 while his figure of perdix has the whorls as round as Siamensis, and though 

 it may belong to the same species as represented by Sowerby's figure 128 in 

 Thes. vol. I, I do not think that it can at all be referred to the Borneensis 

 group, because it appears to want the peculiar straightness of the inner 

 portion of the peristome. 



The solution of this question of identity depends now upon a com- 

 parison of the type-specimens of Sowerby's C. perdix and aquila with a good 

 series of typical Borneensis, as represented in Borneo, near Singapore, 

 Malacca and Penang ; for it will also determine the nomenclature of the 

 latter species. 



The animal of the Penang variety of Borneensis is uniform pale brown 

 with a slight pinkish tinge, and covered with numerous flat greyish warts ; 

 the foot is rather narrow and very long posteriorly, the lateral basal portion 

 below the pedal row is warty, not sulcated ; head slightly darker than the 

 body, tentacles blackish near the tip ; eyes on small bulgings, surrounded by 

 a pale ring ; mantle greyish, thick near the margin. There is scarcely 

 a noticeable difference in the size of the sexes. 



The only other species of Cyclophorus which I have to mention, and which 

 has been described from Penang, is (7, Bfeifferi of Reeve. It belongs to the 

 section of C. tuba with a very much expanded peristome, without any 

 markedly straight inner, or produced basal portion. E. v. Martens (1. cit. 

 p. 134) states that it is probably not constantly different from C. tuba, but, 

 setting aside the more inflated whorls of the latter species, I believe, Bfeifferi 

 also differs from the last by a much more rapid increase of the volutions. 

 In this point, as well as in the flattened and angular shape of the whorls, 

 it, however, quite agrees with expansus, and a large specimen of this last 

 from Tenaserim scarcely at all differs from Reeve's illustration ; I would, 

 therefore, be inclined to regard Bfeifferi as identical with expansus. 



