KnssiLS 01 THE BURLINGTON GROUP. 341 



cue-half its entire length beyond the extreme length of the arms. * 

 They also differ from Batocrinus and agree with Actinocrinites in nearly 

 always perhaps always normally) having the second radial pieces hex- 

 agonal instead of quadrangular, while their body plates are more or less 

 sculptured (generally strongly so) into radiating costa?, usually consist- 

 ing of a single rib for each side of each plate, instead of having the 

 plates even and smooth, merely convex or tumid. In short, the species 

 of these two groups can be distinguished at a glance from specimens 

 even showing the body only. * 



A- thus limited, the genus Actinocrinites would include, along with 

 a number of foreign species, the following American Carboniferous 

 forms, T 



1. ACTIXOCEDCITES, Miller. Section (a). 



A. rerrucosus (=A. asterius, McC.). A. Moris (=A. tenuisculptus, 

 MrC.). A. lobatii*. A. Huniboldtianus. A.jugosus, A. pernodosus, A. ttni- 

 costatus, A. Loicei, A. brontes, etc., of Hall. Also, A. TandeUi and 

 .4. multiradiatu$, Shumard : A. Wachsmuthi. White; and A. scituJus, 

 M. and W. (=A. rusticm. Hall, and A. Sillimani, M. and AT.) ; as well 

 as our A. penicillus and A. deUcattis of this paper, and A. Indianemis, 

 L. and C.. with perhaps several others with which we are not very well 

 acquaintt 

 i'. I b). 



A. multibrachiatus. A.proboddiaIiUj\\ A. c(?lattts, A. clavm, A.Uma- 

 brachintn.ft. A. ovatus, A. securus, A. opusculus, A. excerpt us, A. infrequent. 

 A. thalia, A. thefts, A. thoas. A. loceUtts, A. sexarmatus, A. reticulatus, all 

 described under Actinocrinu* by Prof. Hall. Also, A. Fosteri and 

 ^4.. Hurdianux. McChesney, and our A. longus of this paper. 



It is worthy of note that all the known Burlington species of this 

 group came from the Lower Burlington beds, as has been determined 

 by Mr. WACHSMUTH. by careful observations continued through many 

 years. 



* See figs. 1 and 2. plate 11, Iowa Geo'l Report Vol. I, part ii. 



t See plate x. fig. 10, Iowa Geo'l Report. VoL L part ii. For other examples of this group see figs. 

 13 and 14 same plate, where they may be compared with figs. 7 and 9 of the same plate, representing 

 two species of true Actinocrinites, with arm bases grouped into five protuberant lobes. 



* There are some other described American species not mentioned in this list, which is only intended 

 to include such species as we have had an opportunity to study. 



' Dr. Shumard's A. concinnut belongs here, if not a Steganoerinw*. We have not yet seen a specimen 

 of it showing the rays far enough out to decide positively to which of these groups it belongs. 



|| A. quaternariut, A. quaternariu* tar. tpiniferu-s and A. Themig, Hall, are believed to be varieties of 

 his A . proboteidialu. 



