260 BULLETIN 100, UNITED STATES KATiOXAL MUSEUM. 



adambulacral spines lack the pits and furrows characteristic of 

 the adult, but the number of the spines is the same. The tips are 

 smoothly rounded or truncate. Oral spines 10. This specimen 

 differs from the immature C. clarhi (from station 4407, near Santa 

 Catalina Island, California, 334 to 600 fathoms) in havmg lower 

 tabula to the abactinal plates, relatively slightly larger crowns, a 

 differently formed base (as in adults), smaller pedicellariae, wider 

 superomarginal plates distally (in young clarhi they are not wider 

 than the proximal plates) ; shorter and heavier furrow spines, more 

 crowded adambulacral aramature generallj'^, and no pedicellariae, 

 such as are f requentlj- present in clarhi. 



Type.— Cvit. No. 30551, U.S.N.M. 



Type-locality. — Station 5201, Sogod Bay, southern Leyte Island, 

 554 fathoms, gray sand, mud, bottom temperature 52.8° F. ; 1 speci- 

 men. 



Distribution. — Palawan Passage to Leyte, Philippine Islands, 375 

 to 554 fathoms, gray sand and mud. Temperature range 52.8° to 

 54.4° F. 



Speeimens exanmied. — The type and a specimen from station 

 5348, Palawan Passage (lat. 10°"^57' 45" N.; long. 118° 38' 15" E.) ; 

 375 fathoms, coral sand ; bottom temperature, 56.4° F. 



Reraarhs. — The only species of the Indian region with which this 

 may be confused is Pentagonaster cuenoti Koehler from off southern 

 India, 1,006 fathoms. The resemblance is not close, however, and 

 it is probable that cuenoti belongs to a different section of the genus. 

 Koehler does not state that the radial plates are tabulate, and they 

 do not appear so in the figure. The plates are small, and each is 

 covered by 5 to 7 small roundish granules without order. In the 

 radial regions there are a large number of papular pores irregu- 

 larly disposed. Likewise the marginal plates do not increase in 

 size distad, and there are 7 furrow spines. In '''•Pentagonaster'''' 

 pulvlnus Alcock the plates are close set, and no papulae were visible 

 even after the granules were removed. Although Alcock states that 

 the angular granules show a paxilliform arrangement, I am uncer- 

 tain whether the plates are elevated. I suppose not, as he says the 

 species is related to Pentagonaster 7niral)ills (which is P. placenta^ 

 probably referable to my Sphaeriodiscus) . Pentagonaster {Philon- 

 aster) mortenseni Koehler seems to be closely related to Cera- 

 master arcticus (Verrill) and differs from smithi in having much 

 smaller, higher paxilliform plates with usually 1 or 2 central gran- 

 ules and 6 or 8 peripheral ones very regularly arranged. This 

 arrangement is found on the smaller plates near the margin, the 

 size only changing. 



This species is named for Dr. Hugh M. Smith. 



