347 lYcrrilL 



near low-water mark. The specimens from which the above descrip- 

 tion was made were from Beverly and Chelsea, Mass. At Eastport, 

 Me., and Grand Menan, it is very rare. 



Asterias (Asteracanthion) vulgaris Stimpson, MS. 



Asterias spinosa (pars) Say, Jour. Phil. Acad., v., p. 142, 1825, 

 (not of Linck, which is an Echina.ster, nor of Pennant). Asterias 

 ruhens (pars) Gould, op. cit. p. 345. Asteracanthion ruhens Desor, 

 op. cit. p. 67; Stimpson, Inv. Grand Menan, p. 14. Asterias vulga- 

 ris Stimp. MS., Packard, Canadian Nat. and Geol. Dec, 1863. 

 (?) Asteracanthion pallidus Ag. MS.; A. Ag. Embryol. Asteracanthion. 

 Proc. Am. Acad., 1863 (No description). Asteracanthion Tenney, 

 op. cit. p. 503. fig. 488. 



This species has relatively longer and more gradually tapering rays 

 than the last, with a larger disk. The proportion of the radii is 

 therefore about the same, (1 : 4.5 or 5, in alcoholic specimens, dry 

 specimens being usually so flattened and distorted as to be useless for 

 measurement). Owing to the prominence of the ventral and lateral 

 series of plates and spines, the rays are somewhat angular and de- 

 pressed, and there is a prominent median row of longer spines on the 

 rays above, often traceable to the centre of the disk. The interam- 

 bulacral plates bear usually two, slender, elongated, often pointed 

 spines, so placed on alternate plates as to appear in four rows ; occa- 

 sionally on alternate plates there is but one. The ventral and lateral 

 plates are arranged much as in J.. Forhesii, but the small plates, join- 

 ing the interambulacral, seldom bear spines, and are smaller, with 

 smaller intervening spaces, and in the angle of the rays beneath, there 

 are from six to ten, or even more, irregular, supplementary plates, 

 crowded together, and mostly without spines, while in the preceding 

 species these are absent or represented only by two or three small 

 pieces. The principal ventral plates are very oblique, prominent, and 

 crowded, bearing each from three to five stout, blunt spines, shorter and 

 much thicker than the interambulacral. The lateral plates are sepa- 

 rated from the ventrals by a wide space, with large quadrangular open- 

 ings, the transverse connecting plates being very slender and broken 

 into distinct pieces. In these openings are clusters of very numerous, 

 small " papula " or water-tubes. The lateral plates are smaller than 

 the ventrals, oblong, less oblique, and bear usually two or three short 

 spines, which are much smaller and more pointed than the ventrals, 

 and form a crowded, mostly double row, curving upward near the 

 base of the ray. Exterior to these the lateral and doi-sal area is 

 formed of very slender, openly reticulated plates or ossicles, the trans- 

 verse ones broken Into many small pieces, leaving large openings be- 



