VAN NAME: COMPOUND ASCIDIANS. 355 
The genus SarcobotrvUoides von Drasche, in which re;-ent authors 
have placed this species, is distinguished from Botrvlloides only by 
the greater thickness of the colony. The writer cannot regard it as 
worthy of recognition even as a subgenus. 
This well known northern European species is represented in the 
collections by but few specimens, most of them small ones. The 
following description is based almost entirely on the largest of the 
specimens, which is from Station 2699 off Newfoundland (see below) . 
The colony is on what ajipears to be a section of the stalk of a Bol- 
tenia, completely surrounding and covering it (as well as many of the 
branches of a hydroid also growing on the same object) for a length of 
nearly S cm., reaching a width of over 2 cm. and a thickness of nearly 
1.5 cm. in some places. Though there are considerable areas of the 
surface not occupied by zooids at all, in many places the systems are 
somewhat crowded and their exact limits are often indistinguishable, 
but there appear to be many small oval or elongated ones, and not 
many that are extensively branched. In this respect this species is 
not a typical Botrylloides, but approaches somewhat the genus Botryl- 
lus. Systems occur on all sides of the roughly cylindrical mass of the 
colony. The color of the colony preserved in alcohol in this, as in the 
other specimens, is purple, due chiefly to the deep purple zooids. The 
test is fairly transparent and without much color. It contains the 
branching vessels universally present in this family. 
The zooids are rather large (about 2.3 to 2.7 mm. long, when well 
expanded) and are nearly as broad as in a typical Botryllus. 
The oral tentacles usually number eight, larger and smaller ones 
being placed alternately. Huitfeldt-Kaas and Gottschaldt also give 
this number. Hartmeyer found in addition eight still smaller ones in 
large zooids, making sixteen in all. Such additional tentacles may 
sometimes occur in the American specimen, but if so they are very 
small and rudimentary. 
The branchial sac had 12 or 13 rows of stigmata in the individuals 
in which they could be counted, and three internal longitudinal vessels 
on each side. Between these vessels about three or four stigmata 
intervene; between the median dorsal vessel and the first internal 
longitudinal vessel six or sometimes seven stigmata; between the 
third internal longitudinal vessel and the endostyle also six or seven 
stigmata. For a short distance each side of the endostyle there are no 
stio-mata. 
