246 Mr. F. A. lintlicr r>« 



or figured. It is. however, possiljle to glean some facts con- 

 cerning the genus from the position to vvhicli it was assigned. 

 Being in the Class Adelostella (Austin), it liad a " body 

 covered with closely-jointed calcareous plates, not lobed, and 

 without arms." Being in the Order Colurani(l;Te (Austin"), 

 its body was ''attached by a jointed . . . column." Of the 

 two Families : Sphseronoidcce (Gray) and Echinocrinoidca 

 (Austin) into which that Order was divided, Sycocrinus was 

 ])laced in the former ; we may therefore infer that " pores" 

 wore either "wanting" or "scattered irregularly among 

 the plates," and that the " surf\xee " was "smooth," i.e. 

 devoid of spines. 



In March, 1843, the '' Descriptions of several new Genera 

 and Species of Crinoidea," whose names had been introduced 

 in the previous paper, were published by the Austins, and 

 among them the definitions of Sycocrinus and its three 

 si)ecies (Ann. & Mag. Nat. Hist. vol. xi. p. 206). It is not 

 necessary to reprint these definitions, but, translating them 

 into more modern terminology, we can state the following 

 further facts alleged concerning the genus. In two out 

 of the three species at any rate, the plates of the cup 

 are in three circlets, corresponding a])parently to the cup- 

 plates of a simple crinoid Avith dicyclic base. Eacii of these 

 circlets consists of five ])lates, cxcejjt the proximal circlet 

 (IBB), in which there are three, doubtless formed as usual 

 by fusion of two pairs. Tiie mouth is central and surroxmded 

 or covered, in one of these dicyclic species, by five plates 

 corresponding to the so-called orals, in the other dicyclic 

 species by (it is suggested) a plated integument. Supposed 

 orals are also present in the third species. The anus is 

 lateral ; its position is given more precisely for only one 

 species, and there it is said to be between wliat we should 

 call tiic basal and radial circlets. 



Analysing the definitions of tlie three species given on the 

 same page, we deduce the following : — 



S. clausns : dicyclic ; oral aspect covered by 5 plates ; anus 



between BB and II R. 

 S.jacksoni: monocyclic; oral asj)cct covered by 5 plates ; 



anus lateral ; stem- facet small. 

 S. anapcpldiiiciiiis : (WvyvWc; oral aspect iu)t covered, so 



far as known ; anus projecting at the side. 



The alleged distinction between S. c/ansus and ,S' anapcpta^ 

 menus is not great, since the anus may have l)eeu in the 

 same ])ositi()n in the two species. ,S'. jacksoni, on the other 

 hand, clearly belonged to a did'crent genus. 



