SHALLOW-WATER STARFISHES 3I9 



regions, and the size and form of the marginal plates. The easiest 

 distinctive mark is, perhaps, the flattened and imbricated condition 

 of the inferomarginal spinules. 



I have compared it with a type-specimen of aerstedii, received 

 from Dr. Lutken himself. The upper marginal plates in the latter 

 have two small spines ; the dorsal paxillary spinules are longer ; the 

 lower marginal plates have two distinct rows of larger spines, and 

 the small spinules are more slender and not imbricated, nor flat and 

 scale-like; the adambulacral spines are similar, but more slender, 

 especially the larger central spine of the actinal side, which is, also, 

 less flattened. 



This species is allied to A. calif ornicus, but has coarser paxillary 

 spinules, with a larger central one, and different spinules on the 

 marginal and adambulacral spines. The latter never has spines or 

 tubercles on the upper marginal plates. 



Near San Francisco (Prof. W. E. Ritter). Type in Yale Museum. 



Professor Fisher (op. cit., 191 ifc, p. 60) has given a number of 

 localities for this species, under the name A. armatus. They range 

 from off San Pedro and Long Beach, California, to San Diego, in 

 4 to 130 fathoms. He considers that its range extends to Panama 

 and Ecuador (as armatus), but I consider the southern form distinct. 



VARIATIONS. 

 Professor Fisher has given a detailed description and several 

 figures of this species, and has very fully discussed its variations. 

 Therefore it is not necessary to give many details here. The above 

 description was written in 1904, long before his paper appeared, 

 and was based on a rather average specimen, as the type. 



ASTROPECTEN CALIFORNICUS Fisher. 

 Plate L, figure 5 (details) ; plate c, figure i; plate a, figures i, 2; plate cii, 



figures I, 2. 

 Astropecten californicus Fishes, op. cit., 1906, p. 299; op. cit., 191 16. p. 61, 

 pi. VI, figs. I, 2; pi. VII, fig. I ; pi. L, fig. 5 ; pi. LI, figs. 2, 2a. 



Disk small, but rather thick ; rays five, long, rather narrow, regu- 

 larly tapered, acute. Radii, 17 mm. and yy mm. ; ratio, i : 4.5. 



Upper marginal plates numerous, not very wide, nor much 

 encroaching on the dorsal surface, convex, separated by deep fascio- 

 late grooves, without special spines, but covered with unequal .small 

 .spinules, of which those in two or three rows along the middle are a 

 little larger and capitate or like rounded granules, while the rest are 

 longer, slender and blunt. 



