VAN NAME: SIMPLE ASCIDIANS. 587 
In some large specimens, one or two additional vessels were found 
on each side, thus: 
Right side (5 or 6) (1) (1) (1) 
mdv. en- 
Leftside (1 or 2) (1) (1) (1) 
These vessels, of course excepting the group of the first fold, are sepa- 
rated by an average of about 15 stigmata in the middle part of the 
sac in large individuals; toward the ends of the sac, and in small 
individuals ever^'where, by fewer stigmata. Transverse vessels of 
sac of three sizes regularly arranged, the smallest merely crossing the 
stigmata. Those of the first and second orders together totaled about 
22 in a fair-sized specimen. 
Stomach short and wide, with a small number (about 12 to 16) of 
deep longitudinal plications and a small narrow curved pyloric caecum. 
Intestinal loop small; margin of anus reflected but not lobed, often 
somewhat two-lipped. 
Gonad a slender antero-posterior tube in the right ventral part of 
the body. It is produced posteriorly into a short curved oviduct. 
The small oval testes occupy the part against the mantle, the elongated 
ovary the part against the branchial sac. Specimens collected from 
July to September often contain numerous tailed larvae in the peri- 
branchial cavity. 
This small species is unquestionably the Ascidia carnea of Agassiz, 
as, although his description is totally inadequate to distinguish it 
from the young of other species such as Tethyum partitum Stimpson, 
his statement that it is not immature serves to determine that this 
is the species referred to. Verrill considered this to be the young of 
the species called Tethyum coriaceum in this paper [Cynthia placenta 
Packard] and hence employed the name carnea for both species, or 
in his later papers the specific name tuberculum, for he had concluded 
that both were identical with the Ascidia tuberculum of Fabricius. 
Bjerkan (1908a, p. 9) expresses the belief that this species {D. 
carnea) is identical with D. grossxdaria, an opinion with which the 
present writer cannot agree. 
D. carnea is found from the Banks of Newfoundland and Bay of 
Fundy to Long Island Sound and is rather common in many localities, 
attached to stones and shells in water of moderate depth (39 fathoms 
or less). Type locality, Boston Harbor. 
