12 University of California Publications in Zoology. [VOL. 4 



Branchial Apparatus. Siphons very short and broad, the 

 branchial somewhat larger. Both four-lobed, the lobes distinct 

 and tumid. Tentacles about sixteen in number, large and much 

 branched, the branches arranged rather constantly in pairs of 

 nearly uniform size, and bearing numerous secondary and ter- 

 tiary branchlets (pi. 1, fig. 14). Hypophysis mouth horseshoe- 

 shaped, somewhat broader than long, the ends turned in but not 

 produced into spirals, the two horns of equal length. Dorsal lan- 

 </'t(ts short, slender and numerous. Branchial membrane with ten 

 large folds on the left side and nine on the right, with suggestion 

 of an additional fold on each side next to the endostyle. Each of 

 the largest folds with ten prominent longitudinal vessels on each 

 side, making twenty in all (pi. 1, fig. 16). Transverse vessels dis- 

 tinctly of two sizes. Stigmata small, uniform in size, extending 

 lengthwise with reference to the folds. Endosti/lc, large and 

 tortorous. Ganglion long and narrow, in some specimens ex- 

 tending nearly the entire distance between the two siphons. 



Digestive Tract. Situated on the left side, the loop about one 

 and one-half times as long as broad, the rectal bend short ; stom- 

 ach small, not clearly set off from the intestine; anus with a dis- 

 tinct rim. 



Gonads. Consisting of about five cylindrical masses on the 

 left side and four on the right, those of the left within the intes- 

 tinal loop. 



In the collection are a number of young specimens that are no 

 larger than the largest specimens of H. I'illosa that I have seen, 

 yet the spines are nearly as long and closely crowded in these as in 

 the largest individuals. In no case are they scattered as they are 

 in L'illosa. This species adds another to the considerable number 

 of spiny Cynthias. It belongs to the hilgendorfi section of this 

 Limiip of species, i. c., to the section having the branchial stigmata 

 extending lengthwise with reference to the branchial folds instead 

 of crosswise, as they do in H. echinata and its congeners. Oka 

 (1906) has recently described two other species from the coast of 

 Japan which in all probability belong to the same group, though 

 the important point of the position of the stigmata he does not 

 mention. Oka's species are H. owstoni and //. rittcri. II. okai 

 appears to resemble //. oicstoni more closelv than any of the other 



