S2 JOURNAL OV C0\CHOI.(^(;y, \'0I,. 12, NO. 3, 1U1,V. IQO/. 



somewhat arched or dome-shaped, the dorsal-margin thick, and the 

 whole surface hard and harsh to the touch. The back is covered with 

 large flat warts, as much as 3 mm. in breadth, with intervals of 

 3-4 mm. between them. There are no small warts between the large 

 ones, but near the mantle margin they become smaller and crowded. 

 The warts are lighter in colour than the dorsal surface, which in all 

 specimens shows traces of a considerable amount of deep violet 

 colour. But this colour is not evenly distributed in any of the speci- 

 mens, and one of them suggests that in life the animal is mottled 

 with purple and yellow on both the upper and the lower surface. In 

 some specimens, but not in all, there are traces of a whitish reticula- 

 tion between the warts. The sheaths of the rhinophores are variously 

 developed in the different specimens, but in all are raised and divided 

 into three or four more or less distinct lobes round the opening. On 

 the sides of the sheaths are small tubercles. The branchial pocket 

 is also variously shaped : in most specimens it is crenulate, but in 

 two it is circular and even. There are no tubercles on the edge, but 

 below the edge are one to four rows of small tubercles on the sides. 

 The branchiae are eight in number, with a ninth extra plume in some 

 specimens ; they are tripinnate, but in places only bipinnate. The 

 plumes are tall, with a very broad main rhachis, but rather thin and 

 scanty. Those in front are ampler than those behind. 



The integuments are full of spicules which are specially crowded 

 in the dorsal tubercles ; they are straight or slightly bent, and when 

 perfect somewhat pointed at both ends, but they are never branched 

 or jointed. The mantle margin overhangs the foot on all sides ; it is 

 thick and stiff, and bears on its underside small tubercles ; they are 

 most numerous near the edge, and contain agglomerations of spicules. 

 The tentacles are large and flattened, though it is not clear if this flat 

 shape is natural, or the result of compression. The anterior margin 

 of the foot is grooved, and the upper laminie appears to be notched, 

 though it is hard to say if the notch is natural, since this part is much 

 contracted and wrinkled in all the specimens. 



The interior of the body is infested by enormous numbers of a 

 nematode worm. It is twisted round the various organs, or coiled up 

 in the spaces in tangles resembling bundles of thread : it is especially 

 frequent in the pericardium, in the blood spaces, round the central 

 nervous system, and in the genitalia. It is surprising that the animals 

 can have supported such numbers of parasites in such important 

 organs. Externally, they show no signs of disease, and though the 

 internal tissues are not in good condition, this may be the result of 

 decay as much as of the attacks of the worms. 



When the body is opened the purple blood-gland is a conspicuous 

 object. It is thick and very ample. The buccal parts are also 



