366 PROCEEDINGS OF THE ACADEMY OF [1879. 



21. (?) EUSPIROCRINUS Angelin. 

 1878. Iconogr. Crinoid., Suec. p. 24. 



General form, including arras, short subcylindrical. Calyx 

 cyathiform, unsymmetrical. 



Underbasals five, subequal. Basals five, four of them with 

 acute upper angles; the fifth heptagonal, the upper angle being 

 truncate to meet the second anal, its left upper side resting against 

 the adjoining first radial, the oblique right side against the first 

 anal plate. Radials large, sublunular. Brachials two, wide, very 

 short. 



Arras dichotomizing, and on becoming free coiled up spirally 

 inward. 



Anal area wide, plates large, alternately arranged as in Poterio- 

 crinus. Ventral tube rather slender, and composed of but few 

 exceedingly large plates. 



Vault constructed of five large oral plates; the ambulacral 

 furrows, which divide within the disc for the two main divisions 

 of each ray, covered by alternating pieces ; the median part of 

 the dome closed b3''. rather large apical dome plates. 



Column short, composed of alternately larger and smaller 

 joints; central canal moderately large. 



We place the genus E usp>irocrinus by itself, as it differs from 

 all other Cyathocrinid?e in its peculiar arm structure, in which it 

 somewhat resembles Edriocrinus Hall, and the recent genus Holo- 

 pus D'Orb. It also differs in the construction of the ventral sac, 

 which appears like the proboscis of the Actinocrinidas, except that 

 in Euspiocrinus the inner cavity is large. Pores have not been 

 observed. 



The only known species is, 



1878. Euspirocrinus spiralis Angelin. Iconogr. Crin. Suec, p. 24, pi. 4, fig. 7a-e. 

 Upper Siluria. Gotland, Sweden. 



22. CARABOCRINUS Billings. 



1856. Geol. Surv. Canada, p. 275. 

 1859. Ibid., Decade iv. p. 30. 



Carabocrinus and the three following genera are imperfectly 

 known, and placed here with some doubt; better specimens must 

 be discovered before it can be decided whether they are good 

 genera. 



