REPORT OIST THE NUDIBRAHCHIATA. 
57 
tufts. The oral orifice has a strong triangular labial plate on each side, composed of high 
upright densely set rods. The tongue has (always ?) a naked rliacliis, three large lateral 
teeth on each side, and a shorter or longer series of external teeth. The large prostate 
embraces the seminal vesicles. 
Euplocamus is transitional between Polycera and Triopa on the one hand and Plo- 
camophorus on the other, but presents closer affinities to the latter genus. Only a few 
species 1 are known, all natives of the warmer seas. Nothing is known of their habits 
and development. 
The following is a list of the known species : — 
1. Euplocamus croceus, Philippi. 
Mediterranean. 
2. Euplocamus japonicus, Bergh. 
Japanese Sea. 
3. Euplocamus pacificus, n. sp. 
Pacific. 
Euplocamus pacificus, n. sp. (PI. III. fig. 30 ; PI. IY. figs. 7-24). 
Habitat . — Pacific Ocean, neighbourhood of Kermadec Islands. 
Dentes linguales laterales duo, dentes externi pauci (5-6). 
A single individual was dredged from a depth of 630 fathoms on July 14, 1874, 
between the Kermadec Islands, and was well preserved in alcohol. Its length was 
27 mm., height 10 ‘5 mm., and breadth 9 '5 mm. ; the length of the rhinophoria 5 mm., 
two-thirds at least of which formed the club ; the length of the branchial tufts 4‘6 mm., 
of the dorsal appendages 5 mm.; the breadth of the sole of the foot was about 5 '2 mm., 
the length of the tail 7' 5 mm. The colour was whitish over the whole body, except the 
branchia, which had a tinge of yellow, and the sulphur yellow margins of the leaves of 
the rhinophoria. 
The form of the body is somewhat quadrangular ; the back rather convex. The 
height is greatest in front of the branchia, behind which it gradually decreases ; the sides 
of the body high and convex, and gradually decreasing from the region of the branchia 
backwards ; the foot is narrower than the back. Th e, frontal margin does not project far 
(about 1’2 mm.), it is slightly emarginate in the middle line ; on either side are from 
1 Several species hitherto described belong really to the genera Idalia, Polycera, and Triopa. 
(ZOOL. CHALL, EXP. PART XXVI. — 1884.) 
Cc 8 
