366 VERRILL 



The genus Lebrunaster Perrier, 1891, p. K, 116, type L. paxillosus 

 Perrier, from Patagonia, depth unknown, is known only from this 

 fauna. 



Numerous nominal species of Cycethra have been described from 

 Magellan Strait and the coasts of Patagonia and Terra del Fuego, 

 where the genus is common and variable. 



Ludwig, 1905, reduces them mostly to varieties of C. verrucosa 

 (Phil.). This species includes C. nitida Sladen, Meissner -f- C. elec- 

 tilis Sladen, Leipoldt -+- C. simplex Bell, Meissner -f- C. pinguis 

 Sladen -f- C. ganeriodes Perrier -f- C. elongata Perrier -j- C. media 

 Perrier -f C. asterina Perrier +C. subelectillis Perrier +C. calva Per- 

 rier -f- C. regularis Perrier -f C. asteriscus Perrier. The last eight 

 forms were regarded by Perrier himself as mere varieties of C. sim- 

 plex, as well as some of the others. 



They are common in Magellan Strait and southward to Cape 

 Horn, from low tide to 40 fathoms. Cycethra lahillei de Loriol, 

 1904, p. 25, pi. II, fig. 2, from Gulf of San Mathias, appears to be 

 a distinct species, with short rays, imperfectly developed marginal 

 plates, and slender paxilliform spinules. 



One of the generic types, common to this region and the North 

 Pacific, is Peribolaster, of the family Korethrasteridae, of which only 

 two species are known. P. foliculata Sladen occurred in 45 fathoms, 

 west of Patagonia. P. biserialis Fisher, 1911, ranges from Cali- 

 fornia to Bering Sea, in from 57 to 313 fathoms. 



The family Solasteridae is represented in moderate depths by 

 Solaster australis (Perrier) and Lophaster stellans Sladen, both of 

 which have occurred in from 30 to 40 fathoms. In greater depths 

 several additional species of those genera occur. (See list of deeper- 

 water species below, p. 368.) 



These are genera widely distributed in all seas, especially in rather 

 deep water, coming into shallow water only in the colder regions. 

 Some of the Antarctic species are closely allied to those of the North 

 Pacific and Arctic Ocean, like those of other families from deep water. 



The Pterasteridse are also well represented by several species of 

 Pteraster and Diplopteraster in waters of somewhat greater depths. 

 These are also allied to the corresponding species of the North 

 Atlantic and North Pacific. ( See list of deeper- water species below, 

 p. 368.) 



The genus Retaster, which is represented by two species, does not 

 occur in northern waters, but is found in the Indo-Pacific region, 

 from Cape Good Hope to Australia. The Patagonian species are as 

 follows : 



