222 



ECHINODERMA TA. 



[ALL. 



FIG. 241. Agelacri- 

 nus ciucinnatien- 

 sis. 



ing of a double series of alternating 

 plates, forming convex ridges, consti- 

 tuting part of the upper face, and bear- 

 ing two or more rows of ambulacral 

 pores* ovarian or anal aperture is situ- 

 ated within the azygous interambula- 

 cral area, surrounded by cuneiform 

 plates. Type A. hamiltonensis. 

 billingsi, Chapman, 1860, Can. Jour., vol. 

 5, p. 358, Trenton Gr. 



cincinnatieusis, Roemer, 

 1851, Verb. Naturh, 

 Rhem. Westph., vol. 

 8, p. 372, and Ohio 

 Pal. vol. 1, p. 55, Hud. 

 Riv. Gr. 



dicksoni, Billings, 1857, 

 Rep. of Progr. Geo, 

 Sur. Can., p. 294, and 

 Can. Org. Rem., Dec. 

 ade3,p.84,TrentonGr. 

 hamiltonensis, Vanuxem, 1842, Geo. Rep. 



3d Dist. N. Y., p. 158, Ham. Gr. 

 holbrooki, James, 1887. Jour. Gin. Soc. 

 Nat. Hist., vol. 10, p. 25. Hud. Riv. Gr. 

 kaskaskiensis, see Echinodiscus kaskaski- 



ensis. 



pileus, Hall, 1866, Adv. sheets, 24th Rep. 

 N. Y. St. Mus. Nat. Hist., p. 214, and 

 Ohio Pal., vol. 1, p. 56, Hud. Riv. Gr. 

 septembrachiatus, Miller & Dyer, 1878, 

 Jour. Cin. Soc. Nat. Hist., vol. 1, p. 27, 

 Hud. Riv. Gr. 



squamosus, Meek & Worthen, 1868, Proc. 

 Acad. Nat. Sci. Phil., p. 357, and Geo. 

 Sur. 111., vol. 5, p. 573, Keokuk Gr. 

 stellatus, see Hemicystites stellatus. 

 vorticellatus, Hall/1866, Adv. sheets, 24th 

 Rep. N. Y. St. Mus. Nat. Hist., p. 215, 

 and Ohio Pal., vol. 1, p. 57, Hud. Riv. Gr. 

 ALLAGECRINUS, Etheridge & Carpenter, 1881, 

 Ann. and Mag. Nat. Hist,, p. 281. [Ety. 

 allage, change; krinon, lily.] Calyx 

 minute, pyriform, without ornamenta- 

 tion ; baeals5, anchylosed ; radials 1x5; 

 arms 10; interradials none; column 

 round. Type A. austini. 

 carpenteri, Warhsmnth, 1882, Bull. No. 1, 

 III. St. Mus. Nat. Hist., p. 40, and Geo. 

 Sur. 111., vol. 7, p. 341, Kaskaskia Gr. 

 ALLOCRINUS, Wachstnuth and Springer, (in 

 press,) Geo. Sur. 111., vol. 8, p. 206. 

 [Ety. allos, another ; krinon, lily.] Calyx 

 small ; arms stout ; basals 3, small ; pri- 

 mary radials 3x5, first large, others 

 smaller ; secondary radials 2 or 3, 

 rounded, quadrangular ; arms composed 

 of transverse plates; interradials two 

 or more deeply impressed; column 

 small; canal pentangular. Type A. 

 typus. 



typus, Wachsmuth & Springer, (in press,) 

 Geo. Sur. 111., vol. 8, p. 207, Ni- 

 agara Gr. 



ALLOCYSTITES, n. gen. [Ety. allos, another; 

 kustis, bladder.] Small, irregularly sub- 

 elliptical, tapering below to a small 

 column ; plates polygonal, without defi- 

 nite order of arrangement and of very 



unequal size ; all the plates poriferous ; 

 mouth near the margin of the summit; 

 the plates which form it coyer part of 

 the body, and on approaching the ori- 

 fice curve up so as to form part of the 

 opening. The collector says when 

 found it projected an eighth of an inch, 

 and the plates forming the projection 

 were accidentally broken off. The am- 

 bulacral opening is upon the extreme 

 height of the summit, and projects 

 above the body, where it is covered by 

 minute plates forming a pentagonal star. 

 Type A. hammelli. 



hammelli, n. sp., Niagara Gr. In addi- 

 tion to the characters above ascribed to 

 the genus, the ranges of plates, if in 

 regular series, would form about six 

 series; the first series are ancliylosed 

 so that two plates only can be distin- 

 guished ; in the second range there are 

 seven plates ; above this the plates are 

 extremely variable in form and size, no 

 two of them being alike; onlv four 

 plates are distinguished as forming the 

 mouth, but there is no reasonable doubt 

 there are five, and that one is narrow, 

 and situated between the mouth and 

 ambulacral orifice, as is usual in this 

 lamily of Cystidians. The projecting 

 mouth-plates and elevated ambulacral 

 opening specially characterize thisgenus 

 and species. The specific name is in 

 honor of Mr. J. F. Hammell, of Madison. 

 Indiana, who collected it in Jefferson 

 County. 



FIG 242. Allocystites bammelli. Side and sum- 

 mit view. 



ALLOPROSALLOCRINUS, Casseday & Lyon, 

 1860, Proc. Am. Acad. Arts and Sci., 

 vol. 5, p. 29.] Ety. alloprosallos, inclin- 

 ing first to one side and then to another ; 

 krinon, lily.] Turbinate ; basals 3 ; 

 primary radials 3x5; secondary radials 

 2 x 10 ; regular interradials 1 ; azygous 

 plates 3; vault elevated, bearing a cen- 

 tral tube or proboscis; arms 11 to 13; 

 distinguished from Agaricocrinus by 

 general form and fewer interradials. 

 Type A. conicus. 



conicus, Casseday & Lyon, 1860, Proc. 

 Am. Acad. Arte and Sci., vol. 5, p. 29, 

 Warsaw Gr. 



euconus, see Batocrinus euconus. 



depressus, Casseday & Lyon, 1860, Proc. 

 Am. Acad. Arts and Sci., vol. 5, p. 31, 

 Warsaw Gr. 



