1909.] NATURAL SCIENCES OF PHILADELPHIA. 275 



Setse in prominent flattened fascicles, arranged in two series of 

 about fourteen to sixteen each, those of the anterior row about one- 

 half as long as those of the other. Rather stout (PL IX, fig. 48), pale 

 yellow, slightly curved and tapered to an acute tip, bilimbate with 

 well-marked, lanceolate, entire but striated blades rather wider on 

 the convex side. Uncini in single series pointing forward on somites 

 V to X and on all abdominal somites, in double interlocking series 

 on somites XI to XX, 105 on V, 98 more crowded on VII, and about 

 65 in each row on XII. On abdominal tori their number decreases 

 from before caudad, there being 32 on XXI, 25 on XXXV, etc. Uncini 

 of somites V to VII (PL IX, fig. 49) have the base prolonged into a 

 slender manubrium with a thin membranous border and a prominent 

 anterior angle, the beak is long and slender and the low crest formed 

 of a few large teeth; guard slightly developed. On somites VIII to 

 X the manubrium becomes gradually reduced and the remaining 

 thoracic tori bear uncini of the form shown in fig. 50, which have 

 the base short, without a manubrium, convex below, with slender 

 ligament, well developed guard, stout beak, and high crest of several 

 transverse rows of teeth. Abdominal uncini (fig. 51) are small, with 

 short base convex below and provided with slender anterior and 

 posterior ligaments, no guard and beak and crest nearly as in posterior 

 thoracic uncini. 



The color has faded, but in life is probably chiefly translucent green 

 or olive green, with scattered flakes of white and deep red blood spots 

 behind the ventral plates and below the setigerous tubercles. 



Type locality, San Diego; E. C. Starks, collector. Two specimens, 

 the type a female filled with large eggs. 



Thelepus crispus Johnson. 



Thelepus crispus Johnson, Proc. Bos. Soc. Nat. Hist., XXIX, p. 428; PI. 17, 

 figs. 175-1786. 



Common at both San Diego and Monterey; at the former between 

 tides and at the latter above and below low water. At Monterey Bay 

 specimens were taken at "big tide pool," June 28, 1904, point above 

 Third Beach, July 12, 1904, and dredged at Delmonte wharf, same date. 



Young and half-grown examples possess numerous eyes, but full- 

 grown ones are nearly or quite eyeless. All specimens examined by 

 me have the deep end of the uncini narrower than in Johnson 's figure 

 and the knob terminal with no projection beyond it. The uncini 

 differ constantly from those of T. hamatus in the prominence of the 

 large crest teeth, while the row of smaller apical teeth is very little 

 developed or absent. Those of T. hamatus, on the contrary, have 



