200 Messrs. Austin on new Genera 



Genus Actinocrinites, Miller. 

 Described by its founder. 



A, elephantinus, Austin, sp. 



The perisomic plates agree with the generic type in number 

 and arrangement, but the radiating folds or ridges which or- 

 nament them are less strongly marked and fewer in number. 

 The plates are also smaller in proportion to the size of the 

 animal. Proboscis or oral tube much elongated, in some spe- 

 cimens exceeding two inches in length. Proboscidial plates 

 hexagonal, with an elevated ridge in the centre of each, and 

 which is surrounded by a circle of minute tubercles. Main 

 rays and subdivisions fifty, furnished with numerous tenta- 

 cuta. Column circular, with two small joints intervening be- 

 tween those of larger size. 



A, cataphractus, Austin, sp. 



Def. — The plates surrounding the body agree with the ty- 

 pical character in number and arrangement. The proboscis 

 or oral tube of this species presents many interesting points 

 of structure. It is covered from its base to the apex with a 

 set of abruptly conical plates arranged spirally. The inter- 

 mediate spaces are covered with smaller plates slightly ele- 

 vated in their centres. Both sets, as well as the plates between 

 the rays and proboscis, are beautifully embossed with minute 

 mammiform eminences. The perisomic plates radiate in single 

 ridges. Rays thirty, furnished with long and close-set tenta- 

 cula. Column : it is impossible to define the structure of the 

 column, as no certainty exists respecting it in this or other 

 species, for it is evident that at different seasons considerable 

 modifications took place. 



There is a strongly marked difference between this species 

 and the triacontadactylus, although each possess the same 

 number of rays. The triacontadactylus has its proboscis co- 

 vered with exceedingly minute plates, while those of the cata- 

 phractus are of striking peculiarity. 



A. aculeatus, Austin, sp. 



Def. — Perisomic plates answer to the generic type in num- 

 ber and general arrangement. The radiations are less strongly 

 marked than in some other species. Oral tube elongated and 

 covered with minute plates, most of which are furnished with 

 a thorn-like projection in their centres. Rays and subdivisions 

 forty. Two rows of minute tubercles ornament the outer sides 

 of each of the rays. Column varying according to the period 

 of the year in which the animal died. 



