264 Dr. F. R. Coiuj^er Reed — The genus Homalonotus. 



Plesiacomia for a species H. hrevicaudatus (Desl.), whicli lie regarded 

 as of independent generic rank. 



Hall/ in the same year, acknowledged only one genus Somalonotus, 

 and in his list of references quoted as synonyms Dipleura, Trimerus, 

 Plesiacomia, Brongniartia, dM^Kcenigia. 



Pompecki,* in 1898, put Calymenella, Bergeron, 1890, as a sub- 

 genus of Homalonotus, but did not refer to other previously 

 established subgeneric groups. 



Woodward,^ in 1903, repeated Salter's definition of the genua 

 (with a few alterations) in connexion with his remarks on British 

 Devonian species, and recognized Salter's group, Burmeisteria, 

 as valid. 



Giirich,* in 1908, allowed only one genus, Homalonotus, but took 

 Brongniartia, Trimerus, and Kcenigia as denoting subgenera of the 

 Ordovician and Silurian periods. 



Moberg & Gronwall,* in 1909, discussed Salter's system of 

 classification of Homalonotus in connexion with their description 

 of H. Knighti. 



In 1909 Giirich® introduced a new subgeneric name Digonus for 

 a Devonian group of species, and he considered the subgenera 

 Dipleura and Burmeisteria as worthy of retention. 



Woods,'' in the same year, regarded Homalonotus, Synhomalonotus 

 (Pompecki, 1898), and Calymene as of equal rank and placed them in 

 the family Calymenidae, but did not mention any subgeneric divisions. 



Raymond,^ in 1913, gave as three separate genera the groups 

 Homalonotus, Trimerus, and Dipleura; but Beecher, in the earlier 

 edition (1900) of the same textbook, mentioned only one genus, 

 Homalonotus, with Trimerus as a subgenus. 



A new Brazilian and Turkish subgenus of Lower Devonian age 

 was established by Clarke,® in 1913, under the name Schi%opyge, and 

 the same author employed the name Homalonotus to include the 

 type-species of Salter's Burmeisteria. 



Generic, Subgenekic, ok Geotjp-names in use. 



1. Homalonotus, Konig, 1825. 



The type of the ^envi?, Homalonotus chosen, by Konig is H. Knighti, 

 Konig,^" of the Upper Ludlow beds of England and Sweden. But 

 the generic name has been used for many years in a comprehensive 



^ Hall, Palffiont. New York, vol. vii, p. xxiii, 1888. 



^ Pompecki, Neues Jahrb. f. Miner. Geol., Bd. i, pp. 235-43, 1898. 



^ Woodward, Geol. Mag., Dec. IV, Vol. X, p. 28, 1903. 



' Giirich, Leitfossilien, Lief, i, Camb. Silur., p. 70, pi. xxvi, figs. 1-3, 190S. 



^ Moberg & Gronwall, Om Fyled. Gotlands, Lunds Univ. Arssk., N.F., 

 Af. ii, Bd. V, No. 1, pp. 72-7, 1909. 



** Giirich, Leitfossilien, Lief, ii, Devon, pp. 155-7, 1909. 



^ Woods, Crustacea and Arachnids, vol. iv, Camb. Nat. Hist., section 

 Trilobita, p. 249, 1909. 



® Raymond, in Eastman-Zittel's Textbook of PalcBontology, vol. i, p. 724, 



^ Clarke, Fos?. Dev. Parana (Mon. Serv. Geol. Miner. Brasil, vol. i), 

 pp. 89-101, 1913. 

 ^° Konig, Ico7ies Sectiles, 1825, pi. vii, fig. 85. 



