1 16 VERRILL 



On the whole, especially considering the locality, it is more prob- 

 able that Brandt's original type of A. camtschatica was the same as 

 the present species; but the description is so indefinite and vague 

 that it seems unsafe to use his name, for the species of this group 

 are very numerous. 



Genus Leptasterias Verrill. 



Leptasterias VERRILL, Proc. Boston Soc. Nat. Hist., x, p. 350, 1866. Type, L. 

 tnulleri Sars. Sladen, Voy. Chall., xxx, p. 563, 1889. Perrier, Exp. Trav. 

 et Talism., p. 108. 



An extensive group of small, more or less diplacanthid starfishes, 

 closely related to typical Asterias, usually with a single row of inter- 

 actinal plates and spines. Rays five or six. The more typical forms 

 have slender rays and a small disk, with the dorsal ossicles irregularly 

 arranged ; others have several subimbricated radial rows, with clus- 

 tered spines. It differs especially from typical Asterias in the dimin- 

 ished number and larger size of the dorsal and lateral papulae, and the 

 small number of interactinal plates, of which there is generally only a 

 single row. The eggs and young are carried in clusters, adhering in 

 front of or around the mouth in most if not all the species. The genital 

 pores are on the actinal side, near the mouth. The oviduct is wide 

 and short; the ovarian tubules are few, thick, beaded by the eggs. 

 (See also p. 8). Type, L. mulleri (Sars). 



The most abundant species of Alaska (L. epichlora) is by no 

 means a typical member of this group, for in many respects it is 

 intermediate between it and typical Asterias, especially in having 

 larger clusters of papulae and often two proximal rows, or sometimes 

 three, of interactinal spines when of large size. 



The species of this group are remarkably variable in many cases. 

 This is particularly true of those inhabiting the vast extent and 

 varied localities of the Northwest coast. 



This unusual tendency to form marked, more or less localized 

 varieties is, like the same phenomenon seen in the genus Henricia, 

 probably due to the fact that most, if not all, of the species of these 

 genera carry their young, until they reach the starfish form, attached 

 to the region about the mouth, and consequently have no free- 

 swimming larval stages (brachiolaria) , such as we find in the 

 species of typical Asterias. The free-swimming young of the latter 

 may remain afloat many days, or even weeks, and thus they may be 

 carried long distances by the currents, in one generation, or they 

 may be scattered in different directions over large areas, thus mixing 

 up the young from various localities. 



