Mr. F. M'Coy on some new Palaeozoic Echinodermata. 245 



cated to support a small elongate interscapular plate, and on 

 its side rests a somewhat larger intercostal plate ; scapula 

 about one-third wider than long, pentagonal, the two lower 

 sides concave, and the lower angles very much prolonged to 

 fit between the lanceolate costals ; substance of the joints very 

 thick, projecting far into the visceral cavity, a strong perfo- 

 rated articular ridge runs across the top of the scapulse ; all 

 the plates shghtly convex and smooth. 



Distinguished from the C. calyx by its deeply impressed pelvis 

 and long, lanceolate first-costals. 



Not very uncommon in the carboniferous limestone of Derby- 

 shire. 



(Col. University of Cambridge.) 



{Bemiarticulata^ 

 PoteriocrinuLS nuciformis (M'Coy). 

 Sp. Char. Body subovate, pointed below, constricted above from 

 the upper margins of the scapulse being narrower than their 

 lower portion ; pelvic plates very small, form unknown ; first- 

 costals long, pentagonal, very narrow below, giving a pointed 

 appearance to the lower portion of cup ; second costals large, 

 tumid, subhexagonal, nearly twice the length of the first- 

 costals, a little less wide than long ; scapulas pentagonal, about 

 one-third wider below than above, giving a very perceptible, 

 constricted appearance to the upper part of the cup, articula- 

 tions apparently the whole width of the plate ; irregular in- 

 tercostal large, subhexagonal, supporting two small pentagonal 

 interscapulars ; surface smooth. Length of cup 8 lines, greatest 

 diameter (at second costals) 7 lines. 



This closely resembles the P. Bockschii figured by Geinitz in 

 his 'Grundriss der Versteinerungskunde,' t. 23. f. 13, but of 

 which no description or definition has been published. 



Not uncommon in the carboniferous limestone of Derbyshire. 



{Col. University of Cambridge — two examples.) 



Poteriocrinus crassimanus (M'Coy). 



Sp. Char, Column small, of thin circular joints ; supracolumnar 

 joint supporting five pentagonal first-costals, slightly wider 

 than long, between and above which rest five pentagonal sea- 

 pulce about as long as the costals, but about one-third wider 

 than long, each of which supports one large cuneiform arm- 

 joint, wider than long, from each of which proceed two hands 

 of six joints each, thicker on alternate sides, the last joint 

 cuneiform and supporting two fingers of about thirty-five 

 joints, each wider than long ; costal and scapular plates ra- 



