708 EEPORT OF COMMISSIONER OF FISH AND FISHERIES. [10] 



and stout cylindrical basal articles, and taper uniformly to a bluntly 

 rounded apex. The feet, dorsal cirri, and setae are all very long, and 

 increase in length from the first segment to the middle of the body, and 

 then as regularly decrease. The superior ramus (fig. 7) bears a dorsal, 

 cirrus, which is as long or even longer than its foot ; and a bundle of 

 very delicate capillary setae, as long as the cirrus, and quite numerous; 

 the ventral ramus is just below the dorsal and projects beyond it, form- 

 ing nearly one-half of the foot; it ends in a minute conical cirrus, is 

 obliquely truncated below, and bears on its lower posterior margin a 

 conical ventral cirrus, which projects beyond the apex of the foot by 

 about one-half its length. The ventral ramus has a fan of compound 

 setae (fig. 8) which decrease in length uniformly from the upper to the 

 lower part of the fan ; the appendix of these setae is about one-third the 

 length of the stem. 



The anterior enlarged part of the digestive tract extends through 

 the first four segments ; it is nearly cylindrical, tapering somewhat along 

 the posterior third ; is finely but distinctly transversely striated ; has 

 a deep median dorsal longitudinal incision or depression of varying 

 width. The transverse striae can be seen passing to the bottom of this 

 depression in front, but behind it seems to be carried completely through, 

 giving two bluntly rounded posterior terminations to this organ. Back 

 of this the intestine has a j'ellowish, granular appearance, and for six 

 segments sends diverticula into the feet, one-third as long as the feet. 



One, two, or three segments preceding the anal have rudimentary 

 appendages. The annal segment is much like the others, bears two 

 anal cirri, in all respects similar to the dorsal cirri. Body slightly convex 

 above and below; colorless, except as colored by the contents of the 

 digestive tract ; tapering uniformly, but gradually, from the first seg- 

 ment to the last. 



The largest specimen had 18 setigerous segments. 



Length, 2.55™™ ; width of middle segment, 0.25™™ ; length o5 foot from 

 middle segment, 0.36™™. 



Found near high-water mark in sandy-mud, Wellfleet, Mass. 



The width was about the same in all the specimens, but in most a 

 number of the posterior segments had been lost. 



According to the diagnosis given by Ehlers (Borsten., p. 187), this 

 species is a Hesione. Ehlers does not mention a definite number of 

 tentacular cirri. Grube, in his Annulata Semperiana, speaking of Fal- 

 lacia QuATREFAGES, which is established as a genus because it has four 

 pairs of tentacular cirri on each side, says that this is also the case with 

 Hesione Savigny, as is plainly stated in the preliminary description of 

 the genus, Syst^me des Annelides, p. 9. Grube further claims that the 

 figure of Hesione splendida (1. c, pi. iii, fig. 3) shows six tentacular cirri, 

 and the basal joint of another, on each side, and remarks that the loss 

 of tentacular cirri is common in this group. 



Quatrefages has examined the specimen from which Savigny made 



