338 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 8 



approximatclv the color in life. This specimen is 70 mm long, 75 mm wide 

 and 9 mm high at the test apex, which is about 30 mm from anterior 

 margin. The unpaired lunule is 22 mm long and 1.5 mm wide. The rarity 

 of this well-marked species, more apparent perhaps than real, is probably 

 due to an unusually subterranean habit which defies ordinary trawling and 



dredging. 



Distribution Gulf of California to Panama. 



Type. — Paris Museum? 



Type /ocrt/Z/y.— "Habite.-Localite inconnue.-Collection Michelin." 



Depth. — Shore to 30 fms. 



Specimens examined. — 2 specimens from 1 station. 



Family GassiduHdae 



Cassidulus pacificus (A. Agassiz) 

 Plate 62, Fig. 61 



Pygorhynchus pacificus A. Agassiz, 1863, p. 27. 



Cassidulus pacificus Grant and Hertlein, 1938, p. 108, pi. 13, fig. 6; pi. 29, 



figs. 4, 5 ; pi. 30, fig. 6. 



Mortensen, 1948, Monograph of the Echinoidea, 



IVi, p. 210, pi. 2, figs. 1, 2, 11-13, 19; pi. 11, figs. 2, 



11-13." 

 This interesting Cassiduloid is represented by 19 specimens and frag- 

 ments of another. The fragments are the ventral surface of a large indi- 

 vidual about 50 mm long by 40 mm wide, and half a dozen pieces of the 

 upper part of the test. The chief interest in these pieces is the color, for 

 they have preserved the color of the living animal to a remarkable degree. 

 The ground color is cream color becoming quite yellow along the sides 

 and on the margins of the lower surface. This surface is quite white and 

 unspotted but the upper surface is covered with irregular blotches of 

 Andover green. Around the periproct, more particularly below it, is an 

 evident patch of vinaceous drab. With these fragments, a specimen 

 20 X 17 X 10 mm was taken which is undamaged ; it is nearly white with 

 evidence of cream color and with irregular rather numerous small blotches 

 of purple. The other 18 specimens show considerable diversity; 5 speci- 

 mens are quite brown, the largest one conspicuously blotched at the an- 

 terior end, dorsally with a darker shade; several half grown individuals 

 are nearly white, with faint indications of small dusky blotches; some 

 small specimens are light gray without spots. These small individuals are 

 about 8 mm long. 



i^Thia ^vork unknown to Clark, being published only half a year after his 

 death. _Th. M. 



