MARINE INVERTEBRATA OP GRAND MANAN. 29 



STERNASPIS FOSSOR, St., n. s., Fig. 19. Body subglobular in contraction, narrowed 

 anteriorly, and annulate with fifteen or more slightly elevated rings. These rings 

 are narrow, and dotted with minute papillae toward the posterior or plate-bearing 

 extremity, except on the smooth ventral surface ; while they are broader and bet- 

 ter marked toward the involute anterior terminal opening or mouth. At the pos- 

 terior extremity below are placed two hard, black, corneous, subquadrate plates, 

 nearly joining each other at their anterior interior corners, but separated by the 

 median line, which is continued for a short distance beyond them on the ventral 

 surface of the animal. Each of these plates is indistinctly marked with lines of 

 growth, and bears a prominent diagonal line separating it into two unequal areas, 

 the posterior of which is the largest. From beneath the posterior and the lateral 

 edges of the plates project strong bristles, those from the lateral edges being much 

 the longest. The anterior extremity of the animal, when the mouth is evolved, is 

 bipapillate ; each knob having two or three concentric semicircles of strong short 

 bristles. The general color is cinereous, and the greatest length about one inch. 

 It lives on muddy bottoms in the coralline zone, and when in confinement is very 

 active, boring into the mud with great celerity, in a manner resembling that of 

 the foot of Solen, or perhaps that of the proboscis of Arenicola. 



ANNULATA. 



TUBICOL^. 



SPIRORBIS SPIRILLUM, Lam. Gould, Inv. Mass., 8. On seaweeds at low water, 

 very common. 



S. NAUTILOIOES, Lam., An. sans vert., v. 359. On shells, etc. 



S. VITREA, St. Serpula vitrea, O. Fabr., F. G., p. 382. A specimen was taken on 

 a Pecten in 20 f., which agrees perfectly with the description of Fabricius. 



S. PORRECTA. Serpula porrecta, Miill., 0. Fabr., F. G., p. 378. Found chiefly on 

 /Sertularice and other corallines. 



S. QUADRANGULARIS, St., n. s. Tubes large, thick, and strong, white, somewhat 

 rugose with lines of growth ; under-side flat, upper surface with two strong carinae, 

 one on each side ; so that a transverse section of the tube is a square. Aperture 

 rounded within and turned upwards. Diameter one-eighth of an inch. Taken in 

 10 f. on shells. 



S. GRANULATA. Serpula granulata, Miill., Prodr., 2857. Common on stones, 

 shells, and the carapaces of crabs in 20 to 50 f. 



VERMILIA SERRULA, St., n. s. Tubes thick, very small; the largest having a 



length of one inch, a breadth of one-fortieth of an inch, and a height somewhat 



greater than the breadth. It is generally straight or slightly undulated, with the 



base somewhat expanded, the dorsal carina very prominent, sharp, and furnished 



5 



