398 TRANS. OF THE ACAD. OF SCIENCE. 



I 

 TAXOCRINUS (continued), 

 interscapular, Hall, 1858. Geol. Iowa, vol. i., pt. 2, p. 482, pi. 



1, fig. 3. — Ham. — New Buffalo, Iowa, 

 nuntius — Forbesiocrinus nuntius, Hall, 1862. 15th Rep. Reg. 

 State Cab. New York, p. 124. — Ham. — Ontario Co., New 

 York. 

 Thiemei — Forbesiocrinus Thicmei, Hall, 1861. Des. New Crin., 

 Prelim. Not., p. 8. — 1861. Bost. Jour. Nat. Hist., vol. vii., 

 p. 317. — Enc — Burlington, Iowa. 



TECHNOCRINUS, (Subgenus of Mariacrinus,) Hall, 1859. Pal. N. 



York, vol. iii., p. 139. 

 Andrewsi, Hall, 1859. Pal. N. York, vol. iii., p. 141, pi. 86, fig. 



1-4. — Orisk. — Cumberland, Maryland, 

 sculptus, Hall, 1859. Pal. N. York, vol. iii., p. 143, pi. 86, fig. 1- 



18. — Orisk. — Cumberland, Maryland, 

 spinulosus, Hall, 1859. Pal. N. York, vol. iii., p. 140, pi. 85, fig. 



1-18. — Orisk. — Cumberland, Maryland, 

 striatus, Hall, 1859. Pal. New York, vol. iii., p. 142, pi. 86, fig. 12 



and 5-11. — Orisk. — Cumberland, Maryland. 



THYSANOCRINUSf (Subgenus of Rhodocrinus), Hall, 1852. Pal. 

 N. York, vol. ii., p. 188. 



aculeatus, Hall, 1852. Pal. New York, vol. ii., p. 190, pi. 42, fig. 

 3. — Niag. — Lockport, New York. 



canaliculars, Hall, 1852. Pal. N. York, vol. ii., p. 189, pi. 42, fig. 

 2. — Niag. — Lockport, New York. 



immaturus, Hall, 1852. Pal. N. York, vol. ii., p. 191, pi. 42, fig. 

 4. — Niag. — Lockport, New York. 



liliiformis, Hall, 1852. Pal. N. York, vol. ii., p. 188, pi. 42, fig. 1. 

 — Niag. — Lockport, New York. 



microbasalis — Thysanocrinus {Rhodocrinus) microbasalis, Bil- 

 lings, 1856. Rep. Geol. Surv. Canada, p. 264. — Rhodocri- 

 nus microbasalis, 1859. Canad. Org. Rem., Dec. iv., p. 63, 

 pi. 6, fig. 2. — Trent. — Ottawa, Canada. 



pyriformis — Thysanocrinus {Rhodocrinus) piriformis, Billings, 

 1856. Geol. Surv. Canada, p. 263. — Rhodocrinus pyrifor- 

 mis, 1859. Canad. Org. Rem., Dec. iv., p. 61, pi. 6, fig. 1. 

 Trent. — Ottawa, Canada. 



TREMATOCRINUS, v. Goniasteroidocrinus. 

 VASOCRINUS, v. Cyatiiocrincs. 



ZEACRINUS, (Subgenus of Poteriocrinus,) Troost, 1850. Catalog. 

 Crin. Tenn. in Proc. Amer. Assoc. Camb. Meet., p. 62. — 

 Cupressocrinus, McCoy, 1852. Pal. Foss., p. 117. (Not of 

 Goldfuss.) — Zeacrinus, Hall, 1858. Geol. Iowa, vol. i., pt. 

 2, p. 543. (Comp. with Graphiocrimjs, Koninck & Le Hon.) 



t For the present I retain Thysanocrinus as a subgenus of Rhodocrinus, 

 from which, however, it does not appear to present any very essential dif- 

 ferences of structure. The principal variation from Rhodocrinus consists 

 mainly in the form of the summit, which is turbinate instead of globose or 

 subglobose; there are also fewer interradial plates, and the basals are ru- 

 dimentary 



