340 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY. 



Lower surface of disc naked ; jaws narrow with only two papillae 

 on each side, a squarish one at apex and a small one at outer cor- 

 ner ; 3 slender, sharp arm-spines Hemipholis gracilis 



Disc-scales with more or fewer spines or spinelets, at least near margin. 

 Disc with only a few spinelets, and these short, smooth, and chiefly 



near margin of disc ; radial shields small Ophiactis kroyeri 



Disc covered with thorny spines or stumps or both ; radial shields 

 very large. 

 Disc with long slender spines and few or no thorny stumps 



Ophiothrix magnified 

 Disc with numerous thorny stumps, often with spines also 



Ophiothrix spiculata 

 Arms dichotomously branched Gorgonocephalus panamensis 



Ophioderma panamense. 



C. F. Lutken, 1859. Add. ad. Hist. Oph., pt. 2, p. 91. 

 Plate 8, figure 2. 



Although this species has not been recorded from Peru, it is a common Panamic 

 species, and it is not strange therefore that the " Hassler " expedition should have 

 found it at Payta. There is a single specimen from that locality in the M. C. Z. 

 collection. Adult specimens are as much as 25 mm. across the disc, with arms 

 110-115 mm. long. The color is "greenish gray or brownish, sometimes with a 

 central light spot ; arms similar in color, banded with lighter and darker. Lower 

 surface grayish or greenish white" (Verrill). 



Amphipholis laevidisca. 

 H. L. Clark, 1909. Mem. Aust. Mus., 4, p. 541. 



This species was taken by the " Hassler " at Talcahuano and has not been met 

 with since. It closely resembles A. squamata and was originally recorded as that 

 species, but seems to be quite distinct. The small size and plain colors render 

 these little brittle-stars so inconspicuous they are ordinarily overlooked. The type 

 is about three millimeters across the disc and has lost whatever color markings it 

 may have had ; there is no indication that the outer ends of the radial shields were 



ever lighter colored than the disc itself. 



^ 



Amphipholis pugetana. 



Amphiura Pugetana T. Lyman, 1868. Proc. Boston Soc. Nat. Hist., 7, p. 193. 

 Amphipholis pugetana A. E. Verrill, 1899. Trans. Conn. Acad., 10, p. 312. 



Plate 9, figure 2. 



It is only after much hesitation that I have referred to this species, five small 

 specimens, dredged by Dr. Coker in 2 fathoms off the northeast side of San Lo- 

 renzo Island, near Callao, on February 5, 1907. They are certainly Amphipholis, 



