1880.] 



PROF. F. J. BKLL ON THE TEMNOPLEURID.E. 



425 



line of the interambulacral arcse ; and though not so deep nor so wide 

 as iu T. toreiimaticus, they extend almost to tlie base of the primary 

 tubercles ; on the other side of these tubercles there are narrower and 

 shallower furrows ; and in the middle line of the ambulacral areae 

 there are deep sutural pits: all these depressions are much more 

 distinct above the ambitus than they are on the actinal surface,iu 

 which point they oifer a striking point of difference from T. reevesii. 

 The test is by no means thin ; all the ocular plates are excluded from 

 the anal area ; the outermost, not the innermost, of the three 

 tubercles on the interambulacral plates is the smallest. 

 The following are the more important measurements : — 



Diameter. 



Gray's type. . 37 



32 



Height. 



18 

 [48.6]^ 



16-3 

 [50] 



Spine. 



10-. 5^ 



In other words T. c/ranulosus differs from T. reevesii (i. e. T. rey- 

 naudi) in the facts that : — 



i. The abactinal area is not large ; and the anal area is much 



smaller. 

 ii. All the ocular plates are excluded from the anal area ^. 

 iii. There are sutural furrows and deeper angular pits, 

 iv. The miliaries are much more numerously developed. 



V. There is no specially large anal plate, 

 vi. The actinostome is a good deal smaller. 



These differences appear to me to be sufficient to justify us in re- 

 garding Gray's Toreumatica granulosa as a distinct species ; it is, 

 however, obviously enough a member of the genus Temnopleurus. 



The following is a table of the dimensions of T. reynaudi proper, 

 the T. reevesii of Gray. 



As in the case of the preceding species, we may here note some 



' The numbers in brackets are the percentage results. 

 2 Greatest length measurecl. 



' Gray's tyjje specimen has lost the abactinal plates ; but two specimens col- 

 lected by Capt. St. John iu the Oorean seas are perfect. 



