170 ECHINOIDEA. 



are rather wide. The tuberculation of the test is much more 

 uniform than in many species. 



The periproct is not always longer than broad, and the hinder 

 surface of the test is not straight vertically in fully grown speci- 

 mens, and there may be only two pairs of poriferous plates within 

 the subanal area. 



Test. Greatest diameter of 



Distribution. Both sides of Atlantic from Norway to Spain, and 

 S. Carolina to Bahia. North Sea ; Mediterranean. 0-85 fms. 



a. Lamlash Bay. 



b-ff. Southport. ' Mrs. J. E. Gray. 



h-m. Southport. Edgar A. Smith, Esq. 



n-p. Liverpool. 



q, r. Tenby, March 1889 (low water in sand). 



s, t. Milton Sands, Devon. G. Montagu, Esq. 



u-y. Scilly Islands. 



z-V. Plymouth. 



d. St. Andrews. Dr. Macdonald. 



d'-g' . Montrose. W. Duncan, Esq. 



h'-f. Cromarty and Moray Firths. Dr. A. Sutherland. 



Ji-m'. Zetland. JR. M'Andrew, Esq. 



n'. British. Bohinson Bequest. 



2. Echinocardium pennatifidum. (Plate XYI. fig. 5.) 



Echinocardium pennatifidum, Norm. Rep. Brit. Assoc. 1868, p. 315; 



Hodge, Tr. North. $ Burh. iv. (1872) p. 142, pi. v. figs. 1-5 ; Al. 



Ag. Rev. Ech. (1872-78) pp. Ill & 351, pi. xx. figs. 1 & 2. 

 Echinocardium laevigaster, Al. Ag. Bull. M. C. Z. i. (1869) p. 277. 

 Echinocardium sp., Bell, Ann. N. H. xvii. (1886) p. 516. 

 Amphidotus gibbosus, Barrett, Ann. N. H. xix. (lt>57) p. 38, pi. vii. 



fig. 2 (non Ag.). 



Body less heart-shaped than in E. cordatum, being either rounder 

 or longer ; anterior ambulacrum not in a groove ; spines not quite so 

 silky as in E. cordatum, but the longest in the same position as in 

 it, and of much the same character both on the upper and lower 

 surface. 



The test of an adult is a good deal higher posteriorly than ante- 

 riorly ; the posterior end is deeply curved in its upper half and the 

 periproct is overhung ; the internal fasciole is, or may be, asym- 

 metrical, but the longer half may be on the right or on the left 

 side ; it is some plates farther back from the madreporite than in 

 E. cordatum ; the number of well-marked pores is, in the first 



