REPORT ON THE HOLOTHURIOIDEA. 71 



Deima fastosum, Theel (PL XX. and PL XXI. fig. 1). 



Deima fastosum, Th<5el, Preliminary Report on the Holotliuridaj, pp. 5, 6. 



Body elongated, of almost equal breadth throughout, more than twice as long as broad, 

 largest a little behind its middle. Tentacles very small, perfectly retractile ; their terminal 

 part with about eight small retractile processes. Pedicels eleven or thirteen along each 

 side of the ventral surface ; the posterior pairs small. Processes of each of the lateral 

 ambulacra of the ventral surface four, inflexible and much longer than half the breadth of 

 the body. Processes of each of the dorsal ambulacra four, resembling the preceding in 

 size and shape. Integument hard and brittle, with crowded, larger and smaller, irregularly 

 rounded, perforated plates, covering one another completely or with their edges only ; 

 every plate rising towards its middle into a large, conical knob. 



Colour in alcohol, light grey. Length, 130 mm. Breadth, 58 mm. 



Habitat.— Station 216. February 16, 1875. Lat, 2° 56' N., long. 134° 11' E. 

 Depth, 2000 fathoms ; bottom temperature, 0"9° C. ; globigerina ooze. Two specimens. 



The body is almost perfectly symmetrically bilateral in having the pedicels and 

 processes of the one side exactly corresponding in size as well as in position with those 

 of the other side ; the only asymmetry which may be observed concerns the third 

 pair of dorsal processes, the left one of which is situated a little more posteriorly than 

 the right one. Besides, the processes of the dorsal as well as of the ventral lateral 

 ambulacra form not only four longitudinal rows, but also distinct transverse rows. In 

 the above diagnosis I have stated that the lateral ambulacra of the ventral surface 

 give off four pairs of processes, counting the two hindmost processes of the body 

 as belonging to those ambulacra, though to judge from their position they may 

 belong to the dorsal ambulacra, which is the case with the two foremost processes ; from 

 want of material I have not been able to make a more detailed examination. If the 

 hindmost processes, contrary to my opinion, should really belong to the dorsum, its 

 ambulacra possess of course five pairs of processes, while the lateral ambulacra of the 

 ventral surface are only supplied with three. The ventral surface is flat or slightly 

 concave, while the dorsal one is extremely convex, the body attaining its greatest width 

 in the posterior half. The mouth and anus are on the ventral surface, and the latter is 

 situated a little in front of the hindmost pedicels. The number of pedicels appears to 

 vary in different individuals, the largest specimens which I have had at my disposal 

 having only eleven pairs, while the other individual which is several times smaller 

 carries about thirteen pairs. Thus, as in Oneirophanta, the number of pedicels is not in 

 proportion to the size of the body. The anterior and posterior pairs are small in 

 comparison with the interjacent ones. The pedicels have a conical form, with then base 

 considerably wider than their top, which is capable of being retraeted. Those of the 

 processes which are arranged along the sides of the body lie in the same plane with the 

 ventral surface as in Deima validum, while the others project from the dorsal surface ; 



