ANATOMY OF A COLLECTION OF SLUGS FROM N.W. BORNEO. 299 



covers the shell ; posteriorly the two keels meet on the visceral mass, the right 

 overlapping the left one. Posteriorly the body is sharply keeled, the keel being broken 

 at irregular intervals, giving it a jagged or toothed appearance. Kugse small and 

 indistinct, excepting on the postero-lateral portion, where they stand out conspicuously. 

 Caudal mucous pore small. Peripodial groove distinct. Foot-fringe same colour as 

 body with very faint, closely set, sepia-coloured lineoles. Foot-sole almost white, 

 narrow. 



Length (in alcohol) 2 5 '5 millim. 



Shell membranaceous, thin, almost transparent, slight indication of apical whorl ; 

 stria? faint ; ventrally there is a thin calcareous portion toward the apex. 



Maj. diam. G'8 ; min. diam. 5*5 millim., about. 



Hab. — Kuching, Mt. Penrissen, and Mt. Santubong, N.W. Borneo. 



Generative Organs. — (PL II. figs. 22, 23.) 



The male organ opens into the vestibule as a narrow tube, just beyond which it 

 becomes enlarged and forms an ovoid sac, giving place again to a short tube-like portion 

 which distally again becomes sac-like. At the distal end there is a short diverticulum. 

 The retractor muscle is inserted on the right side at the distal end, almost opposite 

 to which the short vas deferens connects the prostatic canal with the penis. The 

 receptaculum seminis is a simple, pear-shaped, sessile sac, covered in life by the bend of 

 the large dart-gland. There is a well-developed vagina ; the free oviduct is extremely 

 short. The common duct is richly folded. The dart-gland is very large and has a 

 sharp S-shaped bend at about the middle of its length ; distally there is a short 

 retractor muscle. The dart (PI. II. fig. 23) is a hollow tube with a solid calcareous 

 head ; at the base of the head is a small lateral opening. 



IV. The Genus Wiegmannia, n. gen. 



As already pointed out, Wiegmann in 1898 described a slug-like mollusc from 

 Borneo, to which he gave the name Parmarion ? dubius. In the present collection there 

 are four specimens which must be classed in the same genus as P. ? dubius. From the 

 external characters and the internal structure, it is clear that they cannot be placed in 

 the genus Parmarion, Fisch., or Microparmarion, Simr. I therefore propose a new 

 genus for their reception, and have much pleasure in associating with it the name of 

 Herrn Fritz Wiegmann of Jena, whose anatomical studies have so largely added to 

 our knowledge of the mollusca of the Malayan Archipelago. 



In connection with Wiegmann's work (14), I may perhaps be permitted to point 

 out that the Parmarion Jlavescens of Keferstein is not a Parmarion at all, but a 

 true Urocyclus (7); further, that the Parmarion extranea, Fer., undoubtedly belongs 

 to the genus Girasia, sens, str., agreeing, as it does, with the Indian forms, although 

 it is extremely doubtful if the species figured by Semper is the extranea of Ferussac 

 (cf. Godwin-Austen, 4, pp. 217-218). Semper imagined that the structure of 



