174 HAWAIIAN AND OTHER PACIFIC ECHINI. 



Parapneustes reductus. 



Koehler, 1912. Zool. Anz., 39, p. 162. 



A single specimen of this species was secured in 212 fms. near Graham's 

 Land. 



Tripylus. 



Philippi, 1845. Arch. f. Naturg., 11, 1, p. 344. 

 Type, Schizaster (Tripylus) excavatus Philippi, 1845, loc. cit. 



Mortensen's restoration of this genus seems possibly justifiable even though 

 it is very near to the following. The only known species occurs along the coast 

 of southern South America, at least on the west side, but there has been so much 

 confusion between the various species of Abatus, Tripylus, and Tripylaster that 

 the exact limits of the distribution of Tripylus is still uncertain. The latest 

 information on the genus is given by Mortensen (1910. Swedish South Polar 

 Exp. Ech., p. 87-89). 



Tripylus excavatus. 



Schizaster (Tripylus) excavatus, Philippi, 1845. Arch. f. Naturg., 11, 1, p. 344. 

 Tripylus excavatus Troschel, 1851. Arch. f. Naturg., 17, 1, p. 67, 72. 



There is a single specimen, a fine nearly bare test, in the Albatross col- 

 lection. It is 44 mm. long, 44 mm. wide and 25 mm. high. The color is pale 

 pinkish purple above and nearly white beneath, with the fascioles standing out 

 in deep pink-purple. The species is known only from Chile and the Strait of 

 Magellan. The small specimens recorded in the Hassler Echini from off 

 Cape Corrientes, Argentina, prove to be Abatus cavernosas. 



Station 2777. Strait of Magellan. Bott. temp. 20 fms. G. 



Abatus. 



Troschel, 1851. Arch. f. Naturg;.. 17. 1. p. 72 

 Type, Schizaster (Tripylus) ntrrrnosns Philippi. 1846. Arch. 1" Naturg.. 11. 1, p. 345. 



This gonus has boon thoroughly worked over in recenl yours by Morten- 

 sen and Koehler. Mortensen has suoooodod admirably in untangling the snarl 

 into which the early descriptions had gotten and has brought tint clearly the 

 differences between Abatus and Hemiaster, and also those which distinguish 

 the species of the former genus. Koehler has added three now spooios to the 



