SHALLOW-WATER STARFISHES 2O3 



Pedicellaster palceocrystallus SLADEN, Ann. and Mag. Nat. Hist, ser. 5, voL T, 

 p. 216, 1880. Duncan and Sladen, Mem. Echinod. Arctic Sea, W. of Green- 

 land, p. 34, pi. u, figs. 22-26, 1881. 



A single small specimen of this delicate, five-rayed species (diam- 

 eter, 1 6 mm.) occurred in a lot of other small starfishes sent by the 

 National Museum, No. 6123. It was from the Arctic coast of Alaska, 

 near Icy Cape, in 10 to 15 fathoms, mud and sand (Smith coll.), 

 through W. H. Dall, 1874. 



This species is, therefore, circumpolar. It has been taken off 

 Greenland, Grinnell Land, Cape Fraser, Nova Zembla, Beeren Island, 

 etc., and extends southward to the Norwegian coast and to the Gulf 

 of St. Lawrence. Its bathymetrical range is from 15 to 620 fathoms. 



Order SPINULOSA Perrier. 



Stelleridae Spinulosa PERKIER, Nouv. Arch. Mus. Hist. Nat, YI, p. 154. 1884. 

 Spinulosa PERRIER, Exped. Trav. et Talism., pp. 27, 138, 1894. 

 Phanerosonia and Cryptozonia (pars) SLADEN, Voy. Chall., xxx, p. xxiii, 1889. 

 Spinulosa FISHER, op. cit, igub, p. 251 (table of known families). 



This order, established by Perrier, includes cryptozonate (rarely 

 subphanerozonate) starfishes which usually have but two rows of 

 ambulacral feet (four in Diplopteraster) ; ambulacra! plates not 

 crowded; and generally a reticulated or imbricated dorsal skeleton, 

 but rarely, if ever, true paxillae. The ossicles are sometimes isolated 

 or vestigial in deep-sea genera. The pedicellariae are generally lack- 

 ing. When present, they are neither forcipulate nor forficulate. They 

 may be pincer-like, with two or more simple valves, and are always 

 dermal. The marginal plates are nearly always small, and sometimes 

 indistinct. The lower ones are usually the larger. They never 

 form a thick, rigid margin; the margin may be acute or rounded. 

 Papulae may occur both on the dorsal and on the actinal surfaces, 

 but they are restricted to the dorsal surface in most families. 



The odontophores are adambulacral of various forms. The ambu- 

 lacral grooves are usually narrow. The ambulacral feet always have 

 a terminal sucker. The ambulacral ampullae may be single or 

 double. 



Perhaps the structure of the pedicellariae is the most positive char- 

 acter for separating certain genera of this group from some of the 

 aberrant Forcipulosa. 



A large number of the genera do not have free-swimming larvae, 

 but are known to carry their eggs and larvae attached about the 

 mouth, or otherwise, or in a marsupial pouch (gonocodium) , until 



