246 RECORD OF SCIENCE FOR 1886. 



Etheridge, Egbert, Jr., and P. Herbert Carperter — Continued. 



Order Regiilarcs, E. unci C, 1386. 



(1) F iimUy rentrcmitidie, D'Orbigny, 1352 (Eiaend. E. & C, 1836). 



(2) Family Troostoblasiidcc, E. &, C, 1836. 

 (3J Family XudeohlaHtklw, E. & C, 1836. 



I. Subfamily Elwacrinida', E. & C, 1886. 



II. Snhfami\y SchizoMastoidw, E. & C, 1886. 



(4) Family Granatohlaslidce, E. & C, 1886. 



(5) Family Codastcridcc, E. & C, 1836. 



I. Subfamily P/ifc«osc/iiS?ni(?fc, E. & C, 1886. 



II. Subfamily Criiptoschismidw, E. & C, 1836. 

 Order Irrefjiilarcs, E. & C, 1886. 



(6) Family Asfrocriuitidcv, T. & T. Austin, 18J3 (Emend. E. & C, 1836). 



I. Basals uusymmetrical. 



II. Basals symmetrical ; odd ambulacrum linear. 



The followinj^ is an attempt at an abstract of tli<3 work on American forms : 

 Regu lares, E. & C, 1836. 



Pentremitidw, D'Orbigny, 1852 (Emend. E. & C, 1883). 



Pentremiics, Say, 1820 (Emend. E. & C, 1883), type. 



Encrina Godoni, Do France. This genus us restricted is essentially Carbonif- 

 erous and strictly American, with one possible exception, P. oralis, 

 Gold fuss. 



P. Godoni, var. major, var. nov. 



Pentremitida, D'Orbigny, 1349 (Emend. E. & C, 1832). Type Pcniremites 

 Palletti, de Verueuil. This genus is limited to the Devonian Period, and 

 in America to the Hamilton Group, which contains at least two, and per- 

 haps six, species. 



Mesohlastus,* gen. nov. Typo reniremiles a-citiilatits, Roemcr. This is essen- 

 tially a Carboniferous genus, and occurs on both sides of the Atlantic. 

 The authors think it probable that Granatocritnis glaher, M. & W., should 

 be referred to this group, and also some other American species, hitherto 

 described under Granatocrinus. 



Troostohlastidae, E. «fe C, 1886. 



Troostocrinus, F. B. Shumard, 1865 (Emend. E. & C, 1886). 



Type Pentremiies Eeinu-ardlli, Troost. The type species is characteristic of the 

 Niagara Period of America. No Devonian species are known, but if, as 

 the authors suspect, P. Grosrcnori, Shumard. be referable to this genus, it 

 reappeared in the upper strata of the American Carboniferous linicstoue, 



iletahlasins, gen. nov. Ty\)e Pcnircmites liuealns, Shumard. The authors refer 

 doubtfully to this genus, Pentremiics sul)ci/ruidric>is,lia.\\, and Codanter penta- 

 luhus, Hall, from the Niagara group ; most of the forms are from the 

 American Carboniferous system. The type series occurs in the Upper 

 Burlington limestone, two are found in theKeoknk and two more in the 

 Warsaw limestone, though woue are known in the Kaskaskia limestone, so 

 rich in Pentremites. 



Triccelocrinus, Meek & Wovthen, 1868. Type Penirem\len TToodmani, IMeek & 

 Worthen. This is an essentially Carboniferous type, and, so far as we at 

 present know, it is limited to the Keokuk and St. Louis groups of the 

 American Carboniferous system; four species arc known, though it is 

 probable that two of them are identical. Triccelocrinus Meelcianus, sp. 

 nov., Warsaw limestone, Spurgcn Hill, Indiana. 



NucJeohlaslidir, E. &C., 1886. 



I. Subfamily Elaocrlnidai, E. & C, 1883. 



* Mtuof, intermediate. 



