MARINE MOLLUSCA OF THE UNITED STATES. 117 
Genus HERMZA, Loven. 
Ofvers. Kong. Vet. Acad. Handl. 1844. 
1. H. cructaTA, Alex. Agassiz. Fig. 242. 
Gould, Invert. Mass., edit. ii. 2538, t. 17, f. 256. 1870. 
Body very slender, the tail much attenuated; foot narrower 
than the body, obtusely dilated at the anterior angles; head small, 
semicircular; mouth inferior; tentacles dilated and obtusely 
pointed, the superior face longer than the inferior; branchie di- 
lated, shaped much like trefoil or the ace of clubs, the biliary 
organs within having a rude cruciate form; there are seven prin- 
cipal ones on each side, and eight or ten intermediate much 
smaller ones. 
Massachusetts. 
Genus ALDERIA, Allman. 
Thompson, Rep. Faun. Ireland. 1844. 
1. A. HARVARDIENSIS, Agassiz. Fig. 243. 
Gould, Invert. Mass., edit. ii. 254, t. 16, f. 226-228. 1870. 
Animal broad lanceolate, ochreous-brown; foot yellow; lateral 
prolongations of head tentacular; branchiz short, curved, en- 
larging towards the tips, in about six clusters, of two each, on 
either side, of which the lower one is much smaller. 
Length 12, breadth 4 mill. 
Massachusetts; Grand Manan. 
Genus CLG@LIA, Lovén. ' 
Embletonia, Alder and Hancock, Ann. Mag., viii. 294. 1851. 
1. C. FuscaTa, Gould. Fig. 244. 
(Embletonia.) Invert. Mass., edit. ii. 251, t. 16, f. 229-232. 1870. 
Animal subcylindrical, narrowing backwards; tail short, pointed, 
drab-colored; head larger than body, broad angles rounded, 
slightly emarginate; tentacles short; branchiz club-shaped, ar- 
ranged in five or six tufts on each side of the posterior portion 
of the body; angles of foot not dilated. 
Length 4, breadth .66 mill. 
: Massachusetts. 
2. C. REMIGATA, Gould. Fig. 245. 
(Hmbletonia.) Invert. Mass., edit. ii. 252, t. 16, f. 214-217. 1870. 
Animal long, slender, uniform pale-yellow; head large, emargi- 
nate, angles dilated into triangular lobes with blunt points; ten- 
