60 



BULLETIN 76, UNITED STATES NATIONAL MUSEUM. 



and subglobular and the enlarged adambulacral spine is square cut at base of ray. 

 These features will ser\-e to distinguish small specimens from young of californicus 

 and ornat'tss'unm, in which the central granules of paxillie is not more robust than 

 the peripheral ones, and where there arc never superomarginal tubercles or spines. 



Typc-localUy. — "Puerto Portrero, South America, on sandy bottoms, 9 fathoms, 

 II. Cuming, Esq." (Gray). 



Distribution.— B.nng'e^ from San Pedro, California (and jjrobably fi'om north 

 of this point) to Ecuador (Punta St. Elena, Puerto Portrero). Only Cahfomian 

 specimens have been examined, however. Shore to about 30 fathoms. 



Specimens examinerf.— Thirty-four froni San Pedro and San Diego, as follows: 



SpedTnens of Astropccten armatus examined. 



Long Beach, Californi i 



Sao Diego, California 



Sao Diego, CaUrornia, Beacon 3 Shoal 



San Pedro, Calilornia (ll-2)a 



San Pedro, Calltonila (UI-1) 



San Pedro, California ( VI-1 ) 



San Pedro, California (XV-1) 



San Pedro, CaUfomia (XVI-3) 



San Pedro, California (XlX-2) 



No locality 



Nature of bottom. 



sandy . 



seaweed — 



dark-brown mud. 



shore sand 



coarse sand 



102-30 soft sandy mud. 



U. S. Nat. Mus. 

 Stanford University. 

 Albatross, 1904. 

 University of California. 



Do. 



Do. 



o Station and haul. University of California Series. 



Remarks. — This species is so variable that it is difficult to make its positive 

 characters intelligible through the median of description. It bears a great resem- 

 blance to Astropecten duplicatus Gra}-, from which it differs in having broader rays 

 relative to the length, heavier paxillar granules, much stouter and longer infero- 

 marginal spines, and more conspicuously enlarged subambulacral spines. In 

 duplicatus the superomarginal plates encroach more onto the paxillar area (\vidth 

 equals more than one-half paxillar area) and are not nearly so high as in armatus, 

 the ray being more depressed. 



Armatus may be distinguished from the other two Californian astropectens by 

 the presence of at least a few superomarginal spines or tubercles, by the broader 

 and more tumid superomarginal plates, by the enlarged central granules of the 

 paxillaj, by the heavier and more bristling inferomarginal armature, and especially 

 by the chisel-shaped enlarged adambulacral spme, which is broader at tip than 

 at base, and usually more or less hollowed at the end, on the upper (or outer) side, 

 like a gouge. Even young specimens of armatus have a few superomarginal tuber- 

 cles, although these are usually inconspicuous, in lieu of the superomarginal 

 spines the enlarged central granules of paxillse and the specialized adambulacral 

 spine may be used to determine doubtful specimens. 



The name erinaceus has usually been used for this species. Perrier considers 

 Lutken's orstedii and Gray's armatus to be identical with erinaceus, and in view 

 of the great variability of the species, he is probablv correct. The name armatus, 

 however, has page priority over erinaceus. The Astropecten armatus of MuUer 



