FOSSILS OF THE BUJtMNV.TOX GROUP. 349 



rays, although iiot forming a continuous disc as in Strotoc-rinw proper, 

 not grouped into five lobes. Its arms also differ in never bifucatiug 

 after becoming free. For this group we propose the name Pkysetoorinus 

 (v'-DflTyro?, puffed up ; x/>.\ov, a lily, in allusion to the ventricose vault of the 

 typical species, Act. rentricosus, Hall.)! 



The genus Strotocrinus, as here defined, would include the followirg 

 species, all peculiar to the lower Carboniferous rocks of America : 



1. STROTOCRIXUS, M. and AV. (proper). 



Section (a). Species without a proboscis. 8. pemmbrosus,* S. regalia 

 and 8. glyptus, all described under Actinocrinus by Prof. HALL. 



Section (b). Species with a proboscis. 8. cegilops, 8. rudis, 8. liratus, 

 8. vmbrositsj 8. tenuiradiatxx, 8. thohts and -S'. insculptus, all described by 

 Prof. HALL under Actinoerinus. It may also probably include his Act. 

 glans. His A. da-vis is believed to be synonymous with his S. cegilops 

 (sp.) and his Act. subumbrosus a variety of his 8. liratus (sp.) 



2. Subgenus PHYSETOCRLNUS, M. and W. 



P.rentricosiiSj P. cancellatus, P.ornatus and P. reticuJatus, all described 

 by Prof. HALL under Actinocrinus ; also P. subventricosus, described by 

 Prof. McCnESKEY under Actinocrinus. The proposed species senarius, 

 Hall, is believed to be a variety of his A. ornatits. 



In the single character of having only a simple opening in the vault, 

 without the slightest indications of a proboscis, the Physetocrinus group 

 would agree more nearly with the typical section (a) of Strotocrintts than 

 the section (b) does, but in all other characters it is more distinct. 



STROTOCRIXUS? ASPERRLMUS, M. and W. 



PL 8, Fig 3, 

 Strotocrinus aspfrrimus ? MEEK and WORTHEX. Proceed. Acad. Xat. Sci., Phila., 1869, p. 160. 



BODY under medium size, urn-shaped, being a little wider 

 at the top of the third radials than high, with the secon- 

 dary radials and succeeding parts spreading out horizon- 

 tally, but divided by narrow anal and interradial sinuses 

 quite into the body; sides ascending with a gradual expan- 

 sion to the top of the third radials, with a moderately con- 

 vex outline below the middle. Base about twice and a half 

 as wide as high, not thickened or spreading below, but pro- 



; Iowa Geological Report, Vol. 1, part 2, Palwont., pi. 11, fig. 6, a b. 

 * See Vol. n. Geological Report Elinois, p. 188, 1866. 

 t Iowa Report, part 11. pi. ii. fig. 3, a b. 



