38 CALIFORNIA ACADEMY OF SCIENCES. 



The Hercyn-frage and the Helderberge Lime- 

 stone in North America. 



In American Geologist, vol. 7, 1891, p. 109. 



Notes on the genus Acidaspis. 



AiUhor's ed., 1892. Coinninnicated to the N. Y. State Geologist, Dec, 

 1890. In 44th Eep. N. Y. State Mns., 1892. 

 The author proposes the following scheme of classification: 

 Genns Ceratocephala, Warder, 18;^8. 



1. Species having the occipital ring: (a) Smooth, or with a central 

 tnbercle. Orfo7iio;j/e?«raEmmrich, type 0. oroift Emm. (h) With a single 

 large straight median spine. Acidaspis Murchison, type A. hrighti Murch. 

 syn.^can<Ao/oOTrt Conrad, (c) With two straight divergent spines. Cer- 

 atocephala Warder, sensii stricto. Type C. (joniata Warder, (d) With 

 two spirally recurved spines of great size. Dicranurxis Conrad. Type 

 D. hamatiis (Conrad) Hall. 



2. Species with confluent glabellar lobes, obliqiae thoracic pleurte and 

 spineless pygidinm. (e) Selenopeltis Corda. Type S. bitchi Barr. syn. 

 Polyeres Rouault. (f) Ancj/ropt/ge n. subgn. Type Acidaspis romingeri 

 Hall. Ceratocephala goniata Ward. Acidaspis verneuiUi Bai'r. Trape- 

 locera hoernesi Cord. Dicranurus hamatus Conrad. Acidaspis monstrosa 

 Barr., A. brighii Murch., A. monstrosa Barr., A. romingeri Hall. Odon- 

 tojylettra ovata Emm. Selenopeltis stephani Cord. 



— Note on Coroniira aspectans Conrad. The 



Asaj)hus diiiTus Green. 



Author's ed., 1892. Communicated to the N. Y. State Geologist, Dec, 

 1890. In 44th Rep. N. Y. State Mus., 1892, p. 105. 

 Coroniira diurus Green, pi. 4. 



Observations on the Terataspis grandis HalL 



The largest known trilobite. 



Author's ed., 1892. Communicated to the N. Y. State Geologist, Dec, 

 1890. In 44th Eep. N. Y. State Mus., 1892, p. 111. 

 Terataspis grandis Hall, plate. 



Clarke (W. B.) On the occurrence of Trilobites in 

 New South Wales. 



In Quart. Jour. Geol. Soc London, vol. 4, 1848, p. 63 (not descriptive). 



Claypole (E. W.) Note on a large Crustacean from 

 the Catskill group of Pennsylvania. 



In Proc Am. Philos. Soc, Phila., vol. 21, 188.3, p. 236, plate. 

 Dolichocephala n. g., D. lacoana n. sp. 



