■s, belonging to the littoral zone and 

 or three other smaller species {Zeptas- 

 '^ i of the shore species, A. littoralis 



(Stimpson), is a small species, rarely six inches in diameter, (be- 

 longing to the group, Leptasterias) found in the Bay of Fundy 

 and northward to the Gulf of St. Lawrence, both between tides 



and although variable in form, size, color, (. 

 has not yet led to much confusicm. The two others are large and 

 very common species — one southern and the other northern — but 

 with their respective areas overlapping on the New England coast. 

 One of these, A. Forbesii (Desor), extends from the Gulf of 

 Mexico, to Casco Bay, Maine^ and is the most common species on 

 the southern coast of New England. The other, A. vulgaris 

 (Stimp.), extends from Labrador (and probably farther north) to 

 Long Island Sound, where it becomes rare ; it is the most com- 

 mon species north of Cape Cod, and is very abundant on the coast 

 of Maine and northward. Both species Vary extremely in size, 

 form, and color, even when living, and still more so when pre- 

 served by drying. The color of the faded dry specimen, which 

 M. Perrier mentions as distinguishing "vL FabrlcW'' from "A. 

 berylinus,^'' is a perfectly worthless character, yet when living our 

 two species can usually (but not always) be distinguished by the 

 colors, for A. Forbesii {berylinus) is generally greenish, varying 

 to orange and brown, with a bright orange madreporic plate; 

 while ^1. vulgaris is usually reddish, purplish, or violet, varying 

 to yellow and brown, but with a pale buff or cream-colored mad- 

 reporic plate. Moreover, the colors and forms of each vary accord- 

 ing to the sex, and the form varies accordii 



varies, age, dilation with 



of the 



major pcdicellari8e,t and of the adambulacral (or interambulacral) 

 spines give the most available characters for distinguishing the 

 two species under all circumstances, though the firmer skeleton of 

 A. Forbesii is also an important and characteristic feature. 

 In A. Forbesii the major pedicellarim are short, ovate, blunt- 

 pointed, hardly longer than broad ; the adambulacral spines 

 are stout, obtuse, and in most cases many are more or less 

 flattened, and grooved externally, at tip. 



* It is proper that I should state that I have become satisfied that the species 

 described by me as A. Stimpsoni, in 1866, was not weU founded. The study of a 

 far more extensive series of specimens has shown that the specimens thus named 

 young specimens of A. littoralis were also confounded, so that the characters 

 given largely appertain to the young of A. vulgaris. It is probable that most ol 

 the specimens formerly distributed as A. Stimpsoni, were young of A. vulgaru, 

 and such may have been those that M. Perrier says he has examined, though he 

 considers it a good species. . 



f Dr. Stunpson, in 1862, (Proc. Boston Soc. Nat. Hist., vol. viii, p. 262, note) 

 called special attention to the two peculiar forms of pedicellaiise, characteristic of tms 

 .-_:,_ ._. .. ... importance in distinguishing V -''- "" *°'""'^ ^'^^ 



