50 University of California Publications in Zoology. [Vol. 6 



Lower California to San Diego. San Diego M. B. L. : XVIII-1, June 

 12, 1901, 30 fathoms. LI, off Pt. Loma, 25 fathoms. LXII-1, July 20, 

 1901, 17 fathoms. LXVIII-1, July 22, 1901, 30 fathoms. Albatross: March, 

 1898, San Diego. 



Genus Ophiothrix, M. T. 1842. 



Disc set with thorny grains or thorny spines. Radial shields 

 large, triangular, swollen. Numerous crowded tooth papillae 

 forming a vertical oval. Teeth. No mouth papillae. Five to 

 ten arm spines often three times as long as the arm joints. 

 Usually a small, spine-like tentacle scale. The base of the jaw 

 pierced with a hole. Interbrachial spaces swollen. . Two genital 

 openings, beginning outside the mouth shield. Outer arm joints 

 with hooks. 



Ophiothrix spiculata Le Conte. 

 Figs. 38, 39. 

 Proc. Ac-ad. N. Se. Phila., V, p. 318, 1851. 



Diameter of disc 15 mm. Length of arm about 5Vo times 

 diameter of disc. Disc including radial shields covered with 

 thorny spines. Radial shields nearly touching above base of arm. 

 Tooth papillae in a linear vertical oval with a vertical row in the 

 middle. No mouth papillae. Mouth shields compressed radially. 

 Side mouth shields sub-triangular. Genital openings beginning 

 at mouth shield. One small tentacle scale. Vertical arm plates 

 a little broader than long. Dorsal arm plates pentagonal, DA 

 times as long as broad. Seven long, serrated arm spines, the 2nd 

 or 3rd being longest and about 41/2 times the length of arm joint. 

 Color, greenish brown, sometimes yellowish. Arms interrupted 

 with orange bands. A cluster of orange spots near base of each 

 arm on upper side of disc and internal to these the disc is spec- 

 kled with orange (in one case the central area was white while 

 the rest of the animal was colored normally). Mouth region 

 whitish. 



West coast of Central America to Pacific Grove. Shore to 100 fathoms. 

 Very abundant. San Diego M. B. L., stations: VI, San Pedro, outer har- 

 bor, 11 fathoms. VIII, San Pedro, harbor, May 29, 1901. XIV-2, San 

 Pedro, about 100 fathoms. XVI 2, 3, San Pedro, 9 and 13 fathoms. 

 XVIII-1, June 12, 1901, 30 fathoms. XIX-5, about 77 fathoms. XXI-2, 



