314 PROCEEDINGS OF THE ACADEMY OF [1881. 



interradial in other series, contrary to Batocrinus and all other 

 groups of the Actinocrinidae, which in that series have three 

 plates, or, as we express it, also a special anal plate in the second 

 series. In Batocrinus the second primary radials are linear and 

 quadrangular, in Actinocrinus hexagonal and of a similar form as 

 the first radials. The secondary radials in the former contain 

 two or even three pieces, while in the latter the same order of 

 radials, and all others above the first, have but a single series of 

 plates. 



In Batocrinus the arms, from the first joint up, are composed 

 of a double series of small i^ieces, while these plates in Actino- 

 crinus are preceded by two, three or more large cuneate single 

 joints. In both genera the species show a great variability in the 

 number of their arms, but while in Actinocrinus the whole number 

 of arms is equally divided among the rays, in Batocrinus the raj's 

 adjoining the posterior side frequently have the greater number. 

 In the former, all divisions of the ray are given off alternately 

 from opposite sides, the branches remaining simple ; in Bato- 

 crinus^ the divisions are equal, and each branch bifurcates again ; 

 there are, however, rarelj' more than two divisions from each ray, 

 except toward the posterior side, where the inner division of the 

 rays have s^saetimes tw6 additional bifurcations. 



Closer than with Batocrinus are the relations with Gennseo- 

 crinus^ which, as has been stated, occupies an intermediate position 

 between Actinocrinus and Batocrinus, and which, preceding them 

 in geological times, represents a link between the two genera. 



We place McCoy's Fhillijysocrinus provisionally under Actino- 

 crinus, which it resembles very closel}^ in its general habitus. It 

 has the same peculiar ornamentation, is lobed, has a strong sub- 

 central anal tube, nodose vault-pieces, but it has, according to 

 description, four basals and only 2X5 radials. The latter was 

 evidently a mistake, most probably the third radials were strongly 

 bent outward and not preserved. McCoy had only a single 

 specimen for description, and that this was an abnormal one is 

 sulficiently proved by the presence of seven plates in the second 

 range. It is very possible that the malformation made the addi- 

 tional plate in the basal ring necessary, for there is no other 

 specimen with four basals known from the Subcarboniferous. 

 Pictet refers Phillipsocrinus to llelocrinus, which we cannot 

 indorse. / 



