378 W. G. Van Name — Bermuda Ascidians. 



Var. concolor, nov. 



Plate LIII. Figure 53. 



The colony in this variety resembles that of the typical B. nigrum 

 in form, though I have not seen specimens measuring more than 30 

 or 40 mm across. The zooids are slightly larger, and the mantle- 

 musculature appears to be generally weaker, so that in preserved 

 specimens the zouids are not generally found contracted into the 

 compact cylindrical shape which, as already remarked, is rather char- 

 acteristic of B. nigrum. 



In life the color is a brilliant orange; the zooids, and to some 

 extent the test as well, having this color. It mimics quite closely 

 the color of a species of sponge very abundant in the same situations. 

 In specimens preserved in formalin the orange changes to a brown, 

 red-brown, or even purplish. 



Examples were collected in Harrington Sound, Castle Harbor, and 

 at Somerset Id. It appears to be commoner on the reefs, attached 

 to alga?, corals and gorgonians, than it is near low-water mark. 



Var. sarcinum, nov. 



Differs from the tyj>ical B. nigrum in forming a thick, fleshy 

 colony of gelatinous consistency, with thick rounded edges. The 

 type specimen measures about 50 mm across and is from 4 to 8 mm or 

 more in thickness. The zooids (purple in color in the preserved 

 specimen) exactly resemble those of a typical B. nigrum. The gela- 

 tinous test is yellowish with a purplish tinge. It was obtained by 

 Prof. Verrill in 1898. 



There are other specimens in the collection which show characters 

 more or less intermediate between this form and the true nigrum. 



This variety forms a sufficiently thick and massive colony to be 

 placed in the genus tiarcobotrylloides von Drasche, which is distin- 

 guished from Botrylloides only by the thickness of the colony. The 

 writer is inclined to question the necessity of recognizing Sarcobo- 

 trgUoides, even as a subgenus. 



Genus Symplegma Herdrnan, 18S6. 

 Symplegrna viride Herdman. 



Symplegma viride Herdman, Eeport Voy. Challenger, pt. xxxviii, p. 144. pi. 

 xviii, figs. 7-14. 



Plate L. Figure 'J 'J. 



Herdman described under this name a specimen, taken by the 

 Challenger expedition "in shallow water near Bei'muda," forming 

 for it a new genus and placing it, though with some doubt, in the 



