144 PROF. F. J. BELL ON liCHINODERMATA [Feb. 15, 



PsEUDOcucuMis ACicuLA. (Plate XVI. fig. 5.) 



A single specimen of this rather rare species, the spicules of which 

 I have had figured, as their representation seems to be more satis- 

 factory than those of Prof. Semper. 



MUELLERIA MILIARIS. 



Some of the specimens which I associate under this name differ 

 from M. lecanora in that the region of the anus is not lighter than 

 the rest of the dorsal surface ; on the other hand, the sharp distinc- 

 tion between the dark brown of the bivial and the light colour of the 

 trivial surface is an indication of affinity to M. lecanora. Consider- 

 ing the closeness of the resemblances and the slightness of the 

 differences between M. miliaris and M. lecanora, I feel inclined to 

 suggest that the species should be united. One specimen is of a 

 uniform chocolate-brown colour. 



HoLOTHURiA ALBiDA. (Plate XVI. fig. 6.) 



Body elongated, tapering somewhat at either end ; tentacles darker 

 (? twenty) ; suckers sparse, scattered. Body-wall thin ; oesophageal 

 ring very feeble; Polian vesicle double; lungs poorly developed. 

 The specimen examined had no genital tubes. 



The largest specimen was 180 millim. long, had a greatest width of 

 35 miUim., and was 18 millim. wide in the region of the anus. 



The flat plates are very irregular in form ; the turriform bodies 

 have a single connecting bar, and are knobbed at the narrower end, or 

 where the bar is developed ; at the wider end there are also knobs, 

 and these are surrounded by rather coarse spines (Plate XVI. fig. 6). 



The position of this species in the keys of Lampert cannot as 

 yet be exactly determined, owing to the retracted condition of the 

 tentacles ; it clearly belongs to the group of " Aspidochirote Formen 

 mit Stiihlchen und glatteu Schnallen," and those in which the 

 Schnallen are irregular. Like H. immobilis, it has two Polian 

 vesicles ; but it difiers in colour, in the arrangement of its suckers, 

 and the form of its spicules. Like H. pardalis, it has a number of 

 regular plates, but it wants the characteristic marking of that species, 

 and is of much larger size than any known examples. 



HoLOTHURiA CADELLi. (Plate XVI. fig. 7.) 



Body rounded, tapering posteriorly, dark above, lighter below ; 

 prickly papillse, not so numerous or prominent as in U. squamifera, 

 frequently but not always with a white circular base. Body-wall 

 thin. 



Tentacles (retracted) ; oesophageal ring small and inconspicuous, 

 the anterior region so contracted that the disposition of the Polian 

 vesicles cannot be certainly made out. Cuvierian organs in the 

 form of rather numerous stout csecal tubes from half to one inch in 

 length. Lungs well developed. Genital tubes numerous and ex- 

 tensive. 



The flattened spicules are (Plate XVI. fig. 7) of the type of those 

 found in H. albiventer, but the knobs are more numerous, and 



