1883.] SPECIES OF HOLOTHUROIDEA. 59 



mulberry form, the bars net projecting out so far or so freely as 

 they do" in C. ransonnetti. The composing bars are exceedingly 

 stout, and the spaces between them proportionately small. (Plate 

 XV. fig. 1.) , 



Colour brownish yellow or yellowish white. 



Length (skin much corrugated) :—" body " 35; 50; "tail" 

 37 ; 73. Breadth of "body" 15 ; 16 millim. 



A specimen found on an anchor-cable at Wellington, New Zealand 

 (presented by W. Wykeham Perry, Esq.), gives an exact locality 

 for the species ; another specimen was collected by the Antarctic 

 Expedition. 



OcNus vicARius. (Plate XV. fig. 2.) 



In associating this species with the genus Ocms rather than Cu- 

 cumaria, I have to point out that it appears to represent in the 

 Southern Seas Cucumaria cidcigera, and to raise the question as to 

 whether, at present, we have drawn the best and most natural line 

 of demarcation between these two genera. 



Ten tentacles, of which two are shorter than the rest, not fre- 

 quently divided ; body elongated in form ; integument thin but very 

 firm, on account of the rich deposit of calcareous bodies in its sub- 

 stance. The ambulacral suckers in pairs, but the pairs so irregular, 

 though confined to their own areas, that there is almost a zigzag 

 arrangement ; the costate arrangement at the anal extremity is only 

 faintly indicated. The spicules, which are very richly developed 

 in the skin, have, apparently typically, four central holes with at 

 least one complete circlet of smaller holes ; some attain to a great 

 size. The supporting rods in the suckers are richly developed. 



The retractors are slender and rather short ; the component pieces 

 of the buccal armature delicate. The other details of internal 

 structure could not be made out in the specimen dissected. 



Measurements in millim. : — 



Length.. 41; 28; 18-5. Breadth.. 8; 6-5; 4-5. 



Colour (after preservation in spirit for many years) white. 

 Locality : the Antarctic area is hinted at by the specimens having 

 been collected by Sir E. Belcher. 



Thyone MERiDiONALis. (Plate XV. fig. 3.) 



Body truncated in front when the tentacles (in the size of which 

 there is no marked difference) are retracted, tapering very con- 

 siderably at the hinder end ; suckers absent from the greater part of 

 the bivi'al surface, well enough developed above, and diminishing in 

 number on either side as they approach the bivium. Integument 

 thin, except in the more anterior region. No calcareous teeth to the 

 anus. 



Retractors of the proboscis inserted nearly as far back as the 

 middle of the body, very wide at their insertion ; each band divisible 

 into three or four smaller bands. Polian vesicle single, nearly equal 



