132 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [426] 
rowing beneath the surface of the sand, though many of them may also 
occur creeping on its surface. 
The most abundant and characteristic species. of Crustacea are the lob- 
ster, Homarus. Americanus, (p. 313,) the common shrimp, Crangon vul- 
garis, (p. 339, Plate IIT, fig. 10,) the “‘lady-crab,” Platyonichus ocellatus, 
(p. 338, Plate I, fig.4,) the larger hermit-crab, Hupagurus pollicaris, (p. 
313,) the smaller hermit-crab, Eupagurus longicarpus, (p. 313,) Anthura 
brunnea, Conilera concharum, Unciola irrorata, (p. 340, Plate IV, fig. 19.) 
Of Annelids a considerable number of burrowing species occur, and 
also a few tube-dwelling species, which attach their tubes to dead shells; 
among these last are Sabellaria vulgaris (p. 321, Plate X VIL, figs. 88, 88a,) 
and Serpula dianthus, (p. 322.) an 
The Gastropods are not numerous, and but few are peculiar to sandy 
bottoms; the majority found have their proper homes on shelly or 
muddy bottoms and live in much smaller numbers in sandy places; 
others enumerated in the following list inhabit the patches of eel-grass 
and alge that are often scattered over the sandy bottoms in shallow 
water. A few species, however, have their proper homes on the sandy 
bottoms. . Among the most important of these are Lunatia heros, (p. 353, 
130,) Natica pidilla, (p. 354, Plate XXIII, fig. 132,) Cylichna ory eet, 
(Plate XXV, fig. 164,) Utriculus comaticulatue, (Plate XXV, fig. 160.) 
The bivalve shells are more numerous, and most of them are species 
that burrow beneath the surface... The most common and characteristic 
species are Ensatella Americana, (p. 356, Plate XXVI, fig. 182, and 
Plate XXXII, fig. 245,) Siliqua costata, (p. 358, Plate XXXII, fig. 244,) 
Mactra solidissima, (p. 358, Plate XXVIII, fig. 202,) Angulus tener, (p. 
358, Plate XXVI, fig. 180, and Plate XXX, 223, shell;) Tottenia gemma, 
(p- 359, Plate XXX, fig. 220,) Lyonsia hyalina, (p. 358, Plate XX VII, fig. 
194.) In certain localities, where eel-grass grows, the scollop, Peeten 
irradians, (p. 361, Plate XXXII, fig. 243,) occurs in considerable abun- 
dance. The common muscle, Mytilus edulis, (Plate X XI, fig. 234,) occa- 
sionally occurs in patches or beds. Leevicardium Mortoni (p. 358, Plate 
XXIX, fig. 208) is sometimes abundant in sheltered localities. The 
Ceronia arctata appears to be abundant in some places, as it is some- 
times thrown on the sandy beaches in large numbers, but it was seldom 
dredged. The Thracia Conradi lives on sandy bottoms, buried six 
inches or more beneath the surface, but is seldom obtained alive. The 
dead shells were occasionally dredged in Vineyard Sound. 
Very few Ascidians occur. The most frequent one is Molgula arenata, 
(p. 419, Plate XX XIII, fig. 251,) which lives free in the sand and covers 
itself with a coating of closely adherent grains of sand. Another species, 
M. pellucida, is ovcasionally met with ; this also lives free in the sand, but 
does not attach the sand to itself. It has a clean translucent integu- 
ment, a round body, and two tubes which are large and swollen at their 
