214 BULLETIN 76, UNITED STATES NATIONAL MUSEUM. 



Remarks. — Tliis species probably ranges considerably north and south of its 

 present known distribution. It shows no signs of intergradation with G. japoni(M& 

 to which it is more nearly related than to any other known species. From japonicus 

 it dillers in having secondary intermediate abactinal plates on the radial areas, 

 luo-her tabula, typically thinner margin, spaced bead-like actinal intermediate 

 "ranidcs, shorter and more numerous furrow spinelets, much more numerous 

 actinal adambulacral granules. The same characters will serve to distinguish 

 the young also. Small hptoceramvs have much tliinner margins, more numerous 

 abactinal pedicellaria^, more distinctly spaced tabula, and more numerous furrow 

 spinelets than young japonicus. 



The pediccllaria^, especially the actinal, of leptoceramus are higher and have 

 more delicate jaws than those of japonicus. 



CERAMASTER PATAGONICUS (Sladen). 

 PI. 37, fig. 4; pi. 38, figs. 1, 2; pi. 60, fig. 3. 

 rentagonaster palagonlrus Sladen, Challenger Asleroidea, 1889, p. 269, pi. 46. figs. 3, 4: pi. 49, 



3 and 4. 

 Astrogonium granulare? WnrrEAVE-'i, Trans. Royal Soc. Can., vol. 4, 1886 (1887), p. 117 (40 



fathoms, Strait of Georgia, off mouth of Qualicum River). 

 Mediasler patagoniciis Verrill, Trans. Conn. Acad., vol. 10, 1899, p. 145. 



Diagnosis. — Pentagonal, with straight sides and short rays, or arcuate pentago- 

 nal. R = 76 mm.; r = 52 mm.; R = 1.46 r. Abactinal area flat or slightly inflated; 

 body fairly thick; marginal plates massive, the superomarginals more or less tumid, 

 covered with small polygonal crowded granules, except for a bare spot sometimes 

 occupying the whole abactinal face of plate. This bare space ma^^ be quite tumid. 

 Inferomarginals with a bare space on actinal surface. Abactinal surface with 

 regular hexagonal tabula radiall}-, square or rhomboid interradially, these crowned 

 by a very slightly convex group of convex (truncate off South America) polygonal 

 granules, the marginal series being slightly larger; edge of tabula sharply cut (South 

 America) or slightly scafloped (Alaska). A pedicellaria with two narrow to broadlv 

 spatidate jaws stands on a few of the tabula. The jaws fit into special depressions. 

 Actinal intermediate plates rhombic, squarish, or oblong, covered with coarse 

 slightly to distinctly spaced, quadrate, polygonal, or roundish convex (flat-topped. 

 South America) granules. Broadly spatulate two- or three-jawed pedicellarise in 

 variable numbers on actinal surface. Adambulacral plates wider than long. Fur- 

 row spinelets four or five, robust, more or less compressed, untapered, sometimes 

 subquadrate in section, or with broadened tips, subequal, or graduated toward a 

 shorter adoral member. Back of these on actinal surface is a longitudinal row of 

 two or three heavy granules or short stubby spinelets, sometimes compressed in a 

 longitudinal plane, sometimes subquadrate, with rounded tips. Outside of these 

 is a variable number of granules (about five to eight) similar to but more irregular 

 than those of neighboring actinal intermediate plates. A two-jawed spatulate 

 pedicellaria stands on some of the plates. Mouth plates elongate, plane, with a 

 long furrow margin bearing eight or nine quadrate or prismatic blunt spines (the 

 iiuier two quite heavy) similar in character to those of adambulacral. Armature 

 of actiiuil surface variable. 



