14-1 BULLETIN 76, UNITED STATES NATIONAL MUSEUM 



\ mill's varietj rudis, the type of which I have seen, is a giant form of troschelii 

 resembling Plate 61, Figure 1. His variety subnodosa (type from Wrangell, Alaska) 

 is a variant of forma troschelii, with large primary spines somewhat acervate in 

 places, 1 1 16 one of the narrow rayed varieties between forma troschelii and the 

 variety of alveolata in which the alveolations are breaking up and primary spines are 

 differentiating as in Plate 62, Figure 1. I have examined the types of these two 

 varieties in the Yale Museum. 



I have examined the type of Leptasterias macouni Verrill which was taken at 

 Departure Bay, British Columbia, and is now in the Ottawa Museum. It is, I 

 think, a 6-rayed, young, Evasterias troschelii probably forma troschelii. The radii are 

 41 mm. and 5 mm. The outstanding feature of this specimen is the presence of 

 four series of actinal plates (unheard of in a small Leptasterias) and the behavior of 

 the superomarginals, the series of which curves up strongly at the interbrachium. 

 The intennarginal channel is narrow and does not widen at the base. The first 

 series of actinals extends nearly to the tip of ray (within a few inferomarginals of 

 the tip); second row about three-fourths the length; third row, which is quite com- 

 pressed about half the length; there are four or five compressed plates of a fourth 

 row at base of ray (one or two of them have a tiny spinelet). Superomarginals 

 mostly with one spine, occasionally with a shorter fellow; proximal inferomarginals 

 with two, distal with one; first series of actinals proximally with one or two, distally 

 with one; other actinals with one spine. Adambulacral spines, slenderer than the 

 actinals, alternate two and one; on the diplacanthid plates the inner spine is advanced 

 somewhat into the furrow. The primary abactinal spines are mostly short, thick, 

 and stumpy, somewhat variable in size, while the relatively few minor spines are 

 shorter and much slenderer. Most of the carinal plates have one or two stubby 

 major spines and about two minors while the dorsolaterals have usually one major 

 and about two, quite slender, minors. 



Six-rayed examples of Evasterias troschelii are rare. I have one with R 72 mm. 

 from Departure Bay, British Columbia. It is close to the particular variation 

 shown by Plate 60, Figure 1, but the rays are relatively short (R = 4.5 r). 



The largest specimen which I have examined (station 4222) has R 355 mm., 

 r 46 mm., br. 58 mm. 



Forma ALVEOLATA Verrill. emended 



Plate 58, Figures 2, 2a-2c, 5, 7, la, 76; Plate 59, Figures 1, la; Plate 61, Figures 2, 3; Plates 62, 63; 



Plate 66, Figure 1 



? Asterias epichlora Brandt, 1835. 



Asterias epichlora Stimpson, 1857, p. 528. — De Loriol, 1897, p. 19. 



Aslerias brachiata Perrier, 1S75, p. 65. 



Evasterias troschelii "typical form" Verrill, 1914, p. 153, pi. 26, figs. 1 and 2. 



Evasterias troschelii var. alveolata Verrill, 1914, p. 162, pi. 62, fig. 1. 



Evasterias troschelii var. parvispina Verrill, 1914, p. 163, pi. 106, figs. 1, 2. 



Forma alveolata is far from being homogeneous. It is a convenient pigeon hole 

 for a large number of small varieties which differ from typical troschelii in having 

 the abactinal spines, which are coarser than in acanthostoma , arranged in a reticulate 

 pattern. The spines are typically more numerous than in troschelii; and when the 

 spines arc unequal in size, the smaller are much more numerous than in troschelii. 



