48 PROr. A. DENDT ON THE 



the ventral surface, but ia spirit specimens an arrangement ia 

 three broad, ill-defined bands is recognizable. The living animal 

 attains a considerable size, but varies much according to its 

 state o£ contraction. In spirit it becomes very much contracted 

 and deeply corrugated, the conical projections being withdrawn. 

 It is very difficult to prevent the animal from discharging its 

 viscera when one attempts to preserve it. 



The internal anatomy is typical. There is a bunch of long, 

 slender genital tubes on each side of the dorsal mesentery, 

 situated very near the anterior end. There is a pair of well- 

 developed respiratory trees. The calcareous ring (PI. 7. fig. 82) 

 consists of ten short and simple pieces, the radials being larger 

 than the interradials, and both notched posteriorly. The tentacular 

 ampullae are finger-shaped and well developed. There is a single 

 laro-e, inflated Polian vesicle placed ventrally, and a single 

 Tinbranched madreporic canal running forwards in the dorsal 

 mesentery. 



The most abundant spicules are the usual " tables " charac- 

 teristic of the genus (PI. 7. figs. 73-77), with basal plates about 

 0'06 mm. in diameter. In addition to these occur thin, reticulate, 

 bilateral plates (PL 7. figs. 78, 79), as mentioned by Theel, and 

 curved rods (PI. 7. figs. 80, 81). 



One specimen, also found near "Wellington, contains in addition 

 large numbers of another and very peculiar type of spicule in the 

 integument. These spicules are represented in figs. 83-87. 

 They might be described as dichotomously foliaceous, and are 

 apparently in fundamental constitution akin to those described 

 by Bell for Cucumaria inconspicua * from Port Phillip Heads. 

 They measure about 0-03 mm. in greatest diameter. The 

 specimen in which they occur is of a much lighter colour than 

 usual, in spirit being of a mottled yellowish brown. I can, 

 however, detect no other points of distinction. External cha- 

 racters, the number of tentacles (20), the calcareous ring, the 

 single Polian vesicle and madreporic canal, the tentacular am- 

 pullae, all appear to agree with the corresponding structures 

 in S. mollis. Under these circumstances I prefer to await 

 further information before erecting a new species. 



HoiOTHTiEiA HoBSONi, Sutton. 



1879. Holothuria Eobsoni, Hutton, Trans. N. Z. Inst. vol. vi. p. 308. 



1886. Holothuria Robsoni, Theel, ' Challenger ' Holothurioidea, p. 239. 



* Bell, F. J. Proc. Zool. Soc. Lond. 1887, p. 532. 



