ANATOMY OF A COLLECTION OF SLUGS FROM N.W. BORNEO. 301 



of ruo-ge well marked. Mantle finely spotted with black ; posteriorly does not cover 

 the visceral mass ; has a thin shell-border and faint trace of a keel. Extremity of 

 foot truncate. Posterior portion of dorsum bluntly keeled. Rugae ill defined, 

 fairly large laterally. Sulci blackish. Caudal mucous pore a longitudinal vertical 

 slit extending to the foot-sole. Peripodial groove distinct. Foot-fringe same colour 

 as the body with faint black lineoles. Foot-sole yellowish-brown, with two faint 

 chocolate-coloured bands between median and lateral planes ; lateral planes marked 

 by transverse lines, median plane papillated. 



Length (in alcohol) 50 millim., foot-sole 10 millim. Shell dark amber-coloured, 

 membranaceous, faint trace of apical whorl. 



Hab. — Kuching, N.W. Borneo. 



This fine species is the largest I have seen of the genus. The visceral mass is 

 considerably larger than in either of the two following species, and the keel on the 

 mantle is only very feebly developed. 



Generative Organs. — (PI. II. figs. 27, 28.) 



The vestibule is a large, spacious cavity, into which the penis opens on the 

 right side. This latter organ is very characteristic of the genus, differing in its. 

 length, peculiar form, and the presence of a diverticulum, from the same organ in 

 Parmarion and Microparmarion. In the present species it is folded upon itself at 

 a distance of about one-third from its proximal end ; then forming a loop-like 

 portion it enters the distal third ; at the distal end of the loop-like portion, a short 

 retractor muscle is inserted, and at the commencement of the distal third there is 

 a short diverticulum. I looked carefully for any trace of calcareous granules here, 

 but did not succeed in finding any. Gradually tapering to a fine tube, the penis 

 now passes imperceptibly into the long vas deferens, which joins the prostatic 

 portion of the common duct on its left side (PI. II. fig. 27). The receptaculum 

 seminis is a large, pear-shaped, sessile sac, and has, in this species, a short retractor 

 muscle attached to its free end (PI. II. fig. 27). The vagina is a short tubular 

 cavity with the small opening of the receptaculum seminis on the right side — when 

 looked at from the anterior end — and the larger opening of the free-oviduct on 

 the left. This latter organ is rather more than three times the length of the 

 vagina ; it is coiled upon itself, making a single turn, and then passes into the 

 larger, richly convoluted oviducal portion of the common duct, which is also folded 

 upon itself toward the anterior end. A similar condition obtains in all the three 

 new species here described. The albumen gland is large, as is also the flattened, 

 elongated hermaphrodite gland, which latter has a comparatively short and slightly con- 

 voluted duct. The dart-gland is a large and conspicuous organ, lying on the left ventral 

 side. It has the usual fold at about its middle, and a short retractor muscle at its 

 distal end (PI. II. fig. 27). The dart is smaller than in either of the two following- 

 species ; it measures 3*7 millim. in length, is slightly curved, and the body, externally, 

 is not differentiated from the head, which is a solid calcareous tip. 



