20 F. A. BATHEK, CRINOIDEA <>F GOTLAND. 



Sub-order? inadunata monocyclica. 



[nadunata with no infrabasals. 



This division of the Inadunata into two sub-orders characterised l>v the presence or 

 absence of infrabasals is proposed somewhat tentatively, and will be better appreciated after 

 perusal of the follpwing descriptions. It will then be scen that the sub-orders Larviformia 

 .-nid Fistulata cannol well be maintained. Many genera hitherto included in Larviformia 

 liavo quite as good a ventra] sac as soine acknowledged Fistulataj Wachsmuth and Springer 

 in their Jäst paper l ) said, »We now think that the Larviformia should be restricted to 

 forms in which the radials are directly followed by the orals.» But, on the one hand, they 

 retained Symbathocrinus among the Larviformia, although they had previously described 

 and figured interradials as occurfing between the radials and orals in that genus "); while, 

 on the other hand, they excluded Heterocrinus and Calceocrinus, in which it has at all 

 events never been proved that other plates beside orals occur in the tegmen. It will 

 further l>e seen from the ensuing remarks on Pisocrinus, Calceocrinus and Herpetocrinvs 

 that a very large number of Inadunata Monocyclica closely resemble one another, either 

 in the horizontal bisection of certain radials, a character which in Dicyclica is entirely 

 confined to the right posterior radial, or in the greater development of certain other radials. 

 The extreme importanee of these points was admitted by Dr. P. IL Carpenter in the last 

 conversation I had with him, and we both fel t that they should have more weight in 

 classification than the varying extent of tegminal development. 



The Monocyclica will include all genera placed by Wachsmuth and Springer in their 

 Larviformia (1886), with the possible exception of Cupressocrinus and the Gasterocomidae. 

 It is, however, by no means improbable that the proximal plate of these lat ter is a top 

 stem-ossiele rather than a fused infrasabal circlet: this view is confirmed by the appearance 

 of the plate in question in certain specimens of Cupressocrinus Schlotheimi, C. gracilis and 

 C. inflatus in the British Museum, and in Sandbergers figures of Myrtillocrinus. The 

 Monocyclica will further include the HybocrinidsB, Calceocrinidie, Catillocrinidae and possibly 

 Belemnocrinus. Holocrinus will probably not stånd, sincc Dr. A. von Koenen 3 ), following 

 the comparison made by Mr. R. Wagner 4 )> bas shown that the Encriuus Beyrichi of 

 PiCAHD, on which the genus was founded °), is probably a Dadocrinus. 



The Monocyclic genera may be separated according to their strueture in the follow- 

 ing mariner. 

 I. With r. post. R, r. ant. R and 1. ant. I! transversely bisected. 



(a) With no anal plate. 



Haplocrinus. 



(b) With anal supported on upper angle of r. post. K 3 and abutting on 1. post. R. 



Heterocrinus, Ectenoerinus, Ohiocrinus, Anomalocrinus; Phimocrinust?). 



•) Proc. Ac. Nat. Sci. Philndelphia (1890), p. 355; Feb. 1891. 



-) Rev. III, 167, Proc. 1886, p. 91, LM. V, figs. 13, 14. 



;i ) Crinoiden des Muschelkalks», Alth. k. Ges. Wiss. Göttingen, Bd. XXXIV, Phys. kl. 1. p. 6: 1887. 



4 ) Encriniten des unteren Wellenkalkes , Jenaische Zeitschr. Nat, Bd. XX, N. F. XIII, p. 22; 1886. 



•') Wachsmuth and Springer, Rev. Ill, 215, Proc. 1886, p. 139. 



