196 HAWAIIAN AND OTHER PACIFIC ECHINI. 



Sperosoma Grimaldii Koehler. 



Sperosoma Grimaldii Koehler, 1897. Zool. Anz., XX, p. 302. 1898, " Hirondelle" Ech., 



Pis. II, III, etc. 



North Atlantic ; 165-930 fathoms. 



In addition to one of the " Thor " specimens, received in exchange from 

 the Copenhagen Museum, there lies before us a specimen of Sperosoma 

 taken by the " Blake " off Barbados in 399 fathoms. This specimen is 

 only 110 mm. in diameter, but the structure of the actinal ambulacra is 

 the same as in large specimens. The color is reddish purple. This speci- 

 men had been identified as " Phonnosoma Petersii," no part of an actinal 

 ambulacrum having been cleaned for examination of the plates, and the 

 general facies being very much like Petersii. Its pedicellariae are all rather 

 small and agree well with Mortensen's figures of those of Grimaldii. The 

 " Thor " specimen has some very large pedicellariae, but they are widely 

 scattered ; the smaller ones are rather different in form from the published 

 figures, the base of the valves being somewhat swollen. 



Sperosoma quincunciale de Meij. 



SperoBoma quincunciale de Meijere, 1904. " Siboga " Ech., p. 40 ; PI, XIII. figs. 166-176. 



South of Timor ; 490 fathoms. 



The specimens before us, except for some diversity in color and in the 

 arrangement of the feet abactinally, agree well with de Meijere's description. 

 While the general coloration is distinctly violet of some shade, two or 

 three of the specimens have the abactinal surface and the actinal spines 

 quite yellow. None of the specimens are as large as de Meijere's type. 

 They range from 140 to 170 mm. in diameter. In most of the specimens 

 the tube-feet show the quincunx arrangement abactinally quite plainly, 

 but in one or two specimens the foot on the upper secondary plate-ele- 

 ment, instead of being on the same level as that of the lower secondary 

 element of the plate above, is decidedly below it, and the quincunx arrange- 

 ment, is thereby obscured, the first impression being that of a zigzag line of 

 feet. In other respects these specimens are normal, and we see no reason 

 to consider this peculiarity other than individual variation. The actinal 

 primary spines are provided with large and conspicuous white " hoofs." 



Many of the actinal primary spines of these Japanese specimens are in- 

 fested with a parasitic copepod, apparently identical with Echinocheres globosus 



