1891.] Walsh — ' Investigator ' Deep-sea Holothurians. 201 



** I must first notice a very peculiar holothurian, several specimens 



of which were included in the catch When fresh, the animal 



consists of a tough, muscular sac of a yellowish pink colour, enclosed 

 in a thick coating of perfectly transparent, deep violet ■ jelly. Though 

 not sticky or glairy, this jelly is of so delicate a consistence that it was 

 almost impossible to clean the mud from the animal without stripping 

 off the coating. After a short exposure to the action of spirit, this 

 jelly, previously fully 15 mm. thick, shrinks to a thickness of less than 

 5 mm. and becomes comparatively dense. The violet colouring matter 

 dissolves out into the spirit and exhibits a curious affinity for vegetable 

 tissues, deeply staining a paper label which had been placed within 

 the jar. Its attraction for animal tissues though less marked was still 

 very noticeable, the nuclei shewing it best, so that, on microscojDical 

 examination, the animal was found to have become stained in a solution 

 of its own pigment. After hardening in spirit it is sufficiently evident 

 that this jelly-like coating cannot be considered as a secretion, but as an 

 integral part of the tissues of the body wall, as it consists of a plexus of 

 stellate and spindle-shaped cells, enclosing within their meshes many 

 nuclei-form bodies and much hyaline connective substance. The body wall 

 contains but few calcareous bodies. Those present consist of a circular 

 plate, having articulated to it a fan-shaped body so shaped that the 

 whole apparatus is not unlike the badge of a grenadier's cap. As 

 far as could be made out, these bodies appei'tain to the jelly-like layer 

 and not to the dense inner portion of the body wall, which latter appears 

 to be purely muscular. When laid open it is seen that the lungs are 

 very complex and racemose, and that the ambulacral tubes which are 

 very small and straight, give off a number of minute branches to the 

 pedicels. The polian vesicle is of moderate size and simple. It appears 

 to belong to, or be near, the genus Benthodytes of the Elasipod family 

 Psychropotidce, and is doubtless new as it is identifiable with neither 

 of the species in the Challenger monograph. In all probability, many 

 of its allies must share with this species the peculiarity of a jelly-like 

 coating but no mention of any such appearance is made in the above 

 report." 



Length of specimens 100 to 140 mm. — Body soft ; extremities and 

 ventral feet are still of a beautiful purple, the body generally is a dark 

 lavender colour (in spirit). The anterior end of the body has a wide 

 lappet-like fringe furnished with papillae and the border is continued 

 down each side of the flatly cylindrical body and expanded in a less 

 pronounced form as an anal lappet. Along the lateral border there are 

 numerous feet in a single row. Mouth small and ventral ; anus large, 

 patulous and somewhat dorsal, situated just above the anal lappet. 



