﻿142 LEIDY OK THE MARINE LNVERTEBRATA FAUNA OF 



IS. Escharina variabilis, Leidy. (PL XI. fig. 37.) Polypidom encrusting, spreading 

 in circles ; simple or lobate. Polype-cells exceedingly variable : square, oblong square, 

 tubular, oval, ovoid, or flask-formed ; arranged alternately, semi-alternately, in ad- 

 vancing series, or opposite ; more or less convex, or flat, or with a large spheroidal 

 dilatation in advance of the mouth; usually procumbent, occasionally semi-imbricated, 

 and rarely vertical ; when young glistening white, thin, and covered with perforated 

 mamillae ; when old dull white, thick, and reticulated. Mouth terminally lateral or 

 median, usually to the left, circular, with an elevated border, emarginated inferiorly 

 or laterally, with or without a short tubercle below the emargination. Anal aperture 

 triangular, oblique, elevated, protected by a triangular corneous valve, usually situated 

 to the right of the mouth, occasionally to the left, more rarely beneath, sometimes 

 conjoined with the mouth, and not unfrequently entirely absent. Polypes brownish 

 orange color. Found at Point Judith encrusting rocks and shells ; obtained by Mr. 

 S. Ashmead at Great Egg Harbor, N. J., encrusting oyster shells, serpulse, &c. 



This species of Esoharina may have been already described under half a dozen 

 names, but I found it no easy task to determine which they are. The Getteporidas 

 are subject to great variety of form, and require much study before the true species 

 can be ascertained. 



19. Cellularia fastigiata, Blumenb. Polypidom branching dichotomously. 

 Polype cells in alternating pairs, elongated conoidal, with a short spine supero-exter- 

 nally ; mouth large, elliptical, with an entire margin. Found in small bunches attached 

 to fuci. Obtained by Mr. Ashmead, in Great Egg Harbor. 



20. Alcyonidium? pellucidum, Leidy. (PL X. fig. 24.) Polypidom translucent 

 white, attached by narrow fasciculated bases, which are extended in a procumbent 

 manner and then expand into wedge-shaped masses, upon the free, flat surfaces of 

 which the polypes are clustered. Polypes with bright orange colored tentacula?. 

 Attached to rocks, mytili, sponges, &c, at Point. Judith ; abundant. 



The masses of A. pellucidum. from the white, fasciculated points of attachment to 

 the broad free surfaces are up to an inch in thickness. Although I preserved a 

 number of specimens in fresh sea-water for some days, I could not induce the polypes, 

 if they were such, to protrude from their cells, and I only had .the opportunity of ex- 

 amining them in their retracted condition as represented in figure 24, plate X. 



21. Bowerbankia gracilis, Leidy. (PL XL fig. 38.) Polypidom delicate, creeping, 

 branching, white. Cells cylindrical, erect, about one-third of a line in length, Avithout 

 appendages at their orifice, the margin of which is retractile with the inhabitant of the 

 cell. Polype provided with eight ciliated arms. Intestine with a strong gizzard. 

 Point Judith. 



