SHALLOW- WATER STARFISHES 131 



upper marginal spines are numerous, similar to the dorsals, but 

 rather longer ; they stand in oblique clusters on each ossicle. Besides 

 the main row, there are two to four similar spines on the descending 

 apophysis, and on a small connective ossicle, sometimes present, 

 forming an interpolated series between the upper and lower mar- 

 ginals on the basal half of the rays. 



The longer ventral spines form three main rows, besides a few 

 irregular smaller ones. 



The inferomarginal plates are closely united and each usually 

 bears two cylindrical or slightly clavate, blunt spines, decidedly 

 longer and larger than the dorsals ; or sometimes three near the base 

 of the rays, besides one or two smaller ones. The actinal spines 

 form a single row, one to a plate, and do not extend to the tips of the 

 rays ; they are sometimes lacking. 



The adambulacral spines stand two on a plate, but not in regular 

 lines ; they are shorter and more slender than the actinals, but similar 

 in form. 



The superomarginal ossicles are stout, thick, and imbricated, 

 strongly four-lobed. The upper lobe is large and runs slightly 

 obliquely outward ; the large lower lobe or apophysis is elevated in 

 the middle, where it bears several intermediate spines, or it may be 

 overlapped partially by a small interpolated ossicle. There is a row 

 of small papular areas between the apophyses. The inferomarginals 

 are also stout, but smaller, with four short lobes. The actinal plates, 

 near the base of the rays, are smaller, irregularly elliptical, and 

 closely united to the adambulacrals. The apex of the jaws bears a 

 pair of stout peroral spines and a pair of divergent lateral ones, about 

 half as long. On the outer surface of the jaw there are usually one 

 or two pairs of epiorals that are longer and more tapered than the 

 following ones. The ambulacral grooves are unusually wide ; the 

 plates not very crowded; the pores large, not crowded. Dorsal 

 papulae few, in small groups or isolated. 



Minor pedicellariae are very small and occur on nearly all the 

 spines in small groups or singly. Major pedicellariae, of very small 

 size, acute-triangular in form, occur along the inner edges of the 

 ambulacral grooves. 



Pacific Grove, Monterey, California (Prof. W. R. Coe) ; British 

 Columbia. 



This may be regarded as the most perfectly developed variety of 

 L. aqualis. Its characters are probably in part due to its large 

 size, but I have seen others of the same variety not over an inch 

 in diameter. 



