= a a ee 
Hurroy.—On the Bitentaculate Slugs of New Zealand. 159 
The only specimen of J. papillata that I have had for dissection was in 
such a bad state of preservation that I was unable to make out the details of 
the alimentary and reproductive systems, but I saw enough to convince me 
that they are constructed essentially on the same plan as those organs in the 
_ other two species; in fact I think that it may be only a variety of J. biten- 
taculata. I propose, therefore, to give a general account of the anatomy of 
the genus, and also to point out the differences between J. bitentaculata and 
J. marmorea. I have to thank R. W. Fereday, Esq., for living specimens 
of J. bitentaculata which he found on flax (Phormium) at Fendal Town, near 
Christchurch. 
External characters, The anus is situated on the right side, below and 
a little in front of the pulmonary opening. The reproductive organs open 
behind the right eye-peduncle, (fig. 1). There is a mucous pore situated 
on the dorsal groove, just in front of the pulmonary opening. The foot is 
scarcely distinct from the body, and shows no locomotive disc, but after the 
animal has been placed in strong spirit a lateral groove appears on each side, 
and the foot shows three longitudinal grooves, a broad central one, and a 
narrow one on each side, (fig. 2) Twelve to sixteen minute calcareous 
plates form a rudimentary shell. They are situated inside the pulmonary 
cavity ; the largest in front of the opening, and the others forming a row on 
the inner or left side of the opening, (fig. 16). These particles have been 
figured by Dr. Knight, (Trans. Lin. Soc.” xxii., p. 881.) 
Alimentary system (figs. 4 and 5). The buccal mass is large, and of 
the ordinary shape, but the retractor muscles arise from the musculature of 
the foot, immediately under the nerve collar. The length of the radula is 
hot quite twice its breadth, and each half is rolled up into a separate spiral 
(fig. 4 ¢), as figured by Dr. Knight in his paper already quoted. The 
teeth are about 255-1-255, varying slightly in number, and there are about 
130 transverse rows. The central tooth is about ross of an inch in length, 
and varies considerably. In J. marmorea the anterior end is emarginate, 
and there is no central cusp (fig. 9). In J. bitentaculata there is a 
central cusp, and the anterior end is either simple or has a central swelling, 
which is either single or divided into two (figs. 10, 11, and 12). In the 
Single specimen I had of J. papillata the central teeth were like figs. 10 and 
11, but none like fig. 12. There is no distinction between lateral and mar- 
ginal teeth (figs. 18 and 14); all are alike, and similar in all the species. 
They have been very accurately figured by Dr. Knight. The inner laterals 
‘re rather more than ;s5 of an inch in length, and they gradually 
diminish to about half that size at the margin. They are arranged on 
the en acre Hine that form an obtuse angle, pointing anteriorly. 
