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. 



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

 1890. In 44th Kep. N. Y. State Mus., 1892. 

 The author proposes the following scheme of classification: 

 Genus Ceratocejyhala, Warder, 1888. 



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

 tubercle. Odontopleura'Emmric'h, type O.omtoEmm. (b) With a single 

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

 syn. Acantholoma Conrad, (c) With two straight divergent spines. Cer- 

 atocephala Warder, sensu stricto. Type C. goniata Warder. (d) With 

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

 D. hamatus (Conrad) Hall. 



2. Species with confluent glabellar lobes, oblique thoracic pleurae and 

 spineless pygidium. (e) Selenopeltis Corda. Type S. buchi Barr. syn. 

 Polyeres Rouault. (f) Ancyropyge n. subgn. Type Acidaspis romingeri 

 Hall. Ceratocephala goniata Ward. Acidaspis verneuilli Barr. Trape- 

 locera hoernesi Cord. Dicranurus hamatus Conrad. Acidaspis monslrosa 

 Barr., A. brighti^l-arch., A. monstrosa Barr., A. romingeri Hall. Odon- 

 topleura ovata Emm. Selenopeltis stephani Cord. 



Note 011 Coronurd aspectans Conrad. The 



Asaphus diurus Green. 



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

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

 Coronura 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 Rep. 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, 1883, p. 236, plate. 

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



