30 
THE VOYAGE OF H.M.S. CHALLENGER. 
posteriorly is first downwards then upwards; it is covered at the middle by a large lobe 
of the hermaphrodite gland ; when stretched, the gnt measured 11 mm. in length and 75 
mm. in diameter. The inner surface has longitudinal folds, one of which is especially 
developed. The cavity of the gut contained a, quantity of unrecognisable animal 
matter. 
The lobes of the liver, within the papillae, are tuberous; the almost spherical cnido- 
phorous sacs are united to them by a short ligament; they were full of cnidse of oval shape, 
and measuring from ‘005 to '007 mm. 
The pericardium and the contained heart were typical, and also the yellowish-white 
renal syrinx situated in the neighbourhood of the renal pore. 
The yellowish hermaphrodite gland has a length of 7 mm. and a breadth and height 
of about 3 '5 mm. ; it is conical in shape ; along the dorsal surface there is a wide and 
deep furrow for the main hepatic duct; the gland shows traces of division into halves, 
each composed of a considerable number of lobes, which are themselves divided into smaller 
lobules. The lobules have the usual structure, and the testicular portion, which is white 
in colour, is easily distinguished from the yellow ovarian follicles. The somewhat thick 
hermaphrodite duct which takes its rise from the hollowed-out anterior part of the gland, 
is white in colour, and of inconsiderable length, gradually passing into the ampulla. — The 
anterior genital mass is large, 5 '5 mm. long, 4 mm. broad, and 3 - 5 mm. high; about the 
middle of the upper surface there is a square saddle-shaped hollow for the stomach. 
The opaque whitish-yellow ampulla of the hermaphrodite duct is about five times the 
thickness of the duct itself ; it forms the posterior end of the genital mass, and is coiled 
upon itself ; when unrolled it measures about 12 mm. long, by '8 mm. in diameter. The 
male branch immediately becomes the coiled vas deferens ; this is very thick walled and 
white in colour, when unrolled measuring some 13 mm. in length and ‘6 mm. in diameter 
throughout its whole extent ; it passes above into the excavated base of the (invaginated) 
penis. The penis is short and sac-like, about 2 '5 mm. in length, yellowish-white in colour ; 
the cavity of the prseputium is almost entirely filled by the strongly developed conical 
yellowish glans, which is entirely unarmed. The vesicula seminalis is spherical. The 
mucous gland shows many coils, and is chalk- white; the albuminiparous gland is dirty 
There is hardly any doubt that this species is a Rizzolia ; since it agrees so closely 
with that genus in the character of the mandibles, in the armature of the tongue, and the 
structure of the penis ; the ringed form of the rhinophoria is probably merely dependent 
upon contraction. The peculiar structure of the denticles of the mandibular process will 
perhaps render this species easier of recognition. 
