REPORT ON THE HOLOTHURIOIDEA. 43 



pedicels. The dorsal surface with ;in extension of the skin anteriorly constituting a large, 

 very broad, transverse lobe, bearing four rather large branches or processes in its upper 

 margin; and having immediately behind that lobe two small, rudimentary processes on 

 each ambulacrum. Integument very thin and transparent, with calcareous deposits, 

 composed of a long, thin central part and two slightly arcuated arms, diverging from 

 each of its ends ; each arm with a large process, directed outwards. 



Colour in alcohol, light grey, inclining to violet, here and there a little darker ; 

 tentacles, the oral disk and the nerve cords almost black violet. Length, about 60 or 

 70 mm. Breadth, about 35 mm. 



Habitat— Station 271. September 6, 1875. Lat. 0° 33' S., long. 151° 34' W. 

 Depth, 2425 fathoms; bottom temperature, 1'0° C. ; globigerina ooze. One very 

 incomplete specimen. 



The only individual of this species, which has been obtained by the Challenger 

 expedition, is extremely incomplete ; it wants some of the pedicels, parts of the body- 

 wall, the madreporic-canal, and the water-vascular ring ; consequently my description 

 must be very unsatisfactory. To give an idea of the form of this species, it has been 

 necessary to draw the figures in accordance with my opinion of its probable appearance, 

 hence it is possible that I may have made some mistakes. Only five rather large 

 pedicels are left along each side of the body-wall, and two extremely minute ones at the 

 posterior end of the body ; the rest are torn off, and eight, the number mentioned 

 above, may be wrong. All the tentacles (PL XLIV. fig. 5) are broken, except a single 

 one, which has the terminal part beset with a number of small rather branched, and re- 

 tractile processes, two of which are largest ; those processes are provided with a number 

 of retractUe, branched or unbranched, cylindrical papillae (PL XLIV. fig. 7) the ex- 

 tremely thin walls of which seem to be destitute of deposits. The large, and broad four- 

 branched appendage on the anterior part of the back is made up of four large and 

 li »ng processes, which are arranged in a transverse row, and are webbed together by an 

 extension of the integument leaving only their upper half free. These free ends, of 

 which the two middle ones are largest, appear to be of an elongated conical form 

 though rather flattened. These processes are in connection with large, elongated 

 ambulacral cavities, of which those communicating with the largest middle processes 

 are situated a little in front of the other ones. The appendage is veiy flexible and 

 seems capable of being directed upwards, as well as of being bent downwards and 

 forwards, thus covering the tentacles. The thin and transparent integument is covered 

 with small papillae, each containing a calcareous deposit of the above-mentioned shape. 

 The four processes, running out one from each arm, are situated close to the elongated 

 central part of the deposits. As the calcareous deposits are mostly dissolved and only 

 the surrounding membranes are left, it is impossible to decide whether the arms and 

 the processes are spinose or not. 



