344 F. A. Bather — On Hapnlocrinus Victorice. 



on very variable characters. The case is even less hopeful when 

 we consider other species than the type-species, such, as Agriocrinus 

 inermis, which the author himself admits to be intermediate between 

 Hapnlocrinus and Agriocrinus, but which in some respects is even 

 more like Thallocrinus. Voccocrinus seems to be distinct, in its 

 large orals, single suborals or iuterradials, and the position of 

 its anus. We know, it is true, very little about these features in 

 the other forms, but what we do know suggests a somewhat different 

 structure, and it would be well to keep them apart from Coccocriniis. 

 But to split them up into thi-ee genera, is surely inadmissible on 

 the evidence at present available. 



I propose, therefore, to merge all these in one genus ; for this we 

 are bound to take the name of the type-genus of Jaekel's suggested 

 family, viz. Hapalocrinus ; and the type-species will be H. elegans, 

 of which Jaekel has given so complete a description. The family 

 Hapalocrinidse lapses, since the genus falls into the Platycrinidse 

 as defined by Wachsmuth and Springer (" Monogr. N. Amer. 

 Camerata," ii, 642, 1897). Their diagnosisof that family runs thus: — 



"Monocyclic. Brachials and interbrachials only slightly repre- 

 sented in the dorsal cup ; the lower brachials taking more or less the 

 form of free arm-plates ; the lower iuterradials in part interambulacral 

 in position, rarely entirely interbrachial. Radials in contact all 

 around, there being no special anal plate. Basals forming a pentagon." 

 To this must be added : Two pairs of the primitive 5 BB fused, 

 the small unfused B being usually the left, sometimes the right, 

 anterolateral. 



The genus Hapalocrinus ^ may be diagnosed thus : — Unfused 

 B left or right anterolateral. Orals not large or distinct. Inter- 

 brachials (suborals of Jaekel) more than one (at least in post. IR). 

 Ambulacrals (covering plates) visible between orals and inter- 

 brachials. IBr 2 (? sometimes 3). Arms fork once, sometimes twice, 

 varying in this respect in the same species (or even individual). 

 IIBr (and ITIBr when present) uniserial, or slightly in zigzag, 

 bearing alternately disposed pinnules, either on each or on every 

 other brachial, with pinnulars longer than wide. Stem circular in 

 section, with small axial canal, relatively long and slender ; the 

 columnals, especially the nodals, with a median thickening. Cirri 

 are present at the root, and often on the nodals of the rest of the stem. 



To these characters it may be added that some species (e.g., 

 H. elegans, H. Freclii) show axial folds passing from the radial facets 

 to the basals ; and that some species (e.g., R. elegans, H. Frechi, 

 H. retiarius) have an ornament of slight longitudinal grooves on 

 the brachials. 



Coccocriniis differs from Ha'palocrinus in its large, symmetrical 

 orals, which almost cover the ambulacra, its single interbrachials, and 

 (?) the position of the anus. Culicocrinus, which closely resembles 



^ aTraAo's, ' tender,' like roast suckiug-pig or tlie clieeks of a maid, also delicate 

 in health. The extreme appropriateness of the name must excuse its close 

 resemblance to Saphcrimts of the same geological age, as well as to Hoplocrinus, 

 ■with which it is associated by its author. 



