MELOCRINID_E. 269 
the arms. The arrangement of the larger plates at the summit is also irreg- 
ular, being unlike that of orals, which probably are not represented. Anal 
opening excentric, at the summit of a small protuberance. Column round ; 
axial canal large, pentalobate, the lobes directed interradially, except in one 
species in which the stem is pentangular and the central canal radially 
disposed. 
Distribution. — Glyptocrinus, as now amended, is confined to the Trenton 
and Hudson River groups, and probably is restricted to America. 
Type of the genus. — Glyplocrinus decadactylus. 
Remarks. —The genus agrees in the uniserial arms and its general 
structure with Mariacrinus, but that has four basals instead of five. It 
resembles Compsocrinus, which has also four basals, but an anal plate in 
line with the radials, which throws it into the Batocrinide. 
The European species referred to Glyptocrinus, with the possible excep- 
tion of G. basilis, belong to other genera. The specimens described under 
the name Glyptociinus globularis by Nicholson and Etheridge probably belong 
to Archeocrinus. They evidently had infrabasals, for the mterradials rest 
upon the basals, and they probably had biserial arms. 
The following species either are synonyms, undeterminable, or are 
removed from Glyptocrinus to other genera 
Glyptocrinus parvus Haun, referred to. . . . . Pecimen eee hevyciocrinas: 
e angularis MrLLER and Dyer, synonym of . . « . Ptychocrinus parvus. 
ce gracilis WETHERBY, Synonymof .. . . . . . Ptychocrinus parvus. 
G Harrisi Mruurr, referred to. . . . . . . . « Compsocrinus. 
& Carleyi Hawn, a pee en eee. eeMariacriniuss 
a miamiensis MILLER, “ Sera ncmctadel sees (COTUDSOCTINGES: 
ce Baeri MEEK, us eg oo o o- 6 6 YGonEnpue 
#6 expansus PHILLIPS, “ 5 oo bf oo Oo o oo Oe OIRS 
c armosus McCuEsneEy, “ Us) Ee cA-umch Emo /LOTOcT-eTeTS 
“ siphonatus Hauu, synonym of 7 2 se = « . Stphonocrinusianmosus: 
fe nobilis Haun, referred to . . . . . . . + . « Sitphonocrinus. 
o: cognatus Mituer, synomymof. . . . . . . . Reteocrinus Onealli. 
as O’ Nealli (Nealli) Hatt, “ Benue eur EER CTCOCIZIUUS. 
< lacunosus BILLINGS, Os ined cen wre EAT Chceocr zits. 
a subnodosus WaAucotr, “ 2 ee ee ee) 6 Rhaphanoecrinus. 
se sculptus MILLER, fi - 7. 1. » «© « « » dehaphanoermus. 
Is argutus WALcoTT, Us een NCU nent mcd SCELICLOCT UNIS. 
a priscus BILLINGS, u: . . . . . « Periglyptocrinus. 
tai 
jfimbriatus SHuMARD, qdersemmnble! 
libanus SArF¥FoRD, not defined. 
plumosus Haut, detached column and arms. 
quinquepartitus BituinGs, detached column and arms. 
Pattersoni M1uLER, undeterminable. 
