F. R. Coivper Reed — On the Phacopidce. 



17S 



may be given, irrespective of questions of synonymy or pre- 

 occupation, which will be dealt with subsequently : — 



Acaste, Goldfuss, 1843. 

 Asteropyge, Corda, 1847. 

 CJiasmops, McCoy, 1849. 

 Goronura, Hall & Clarke, 1888. 

 Corycephalus, Hall & Clarke, 1888. 

 CrypJuBus, Green, 1837. 

 Gnjphina, Oehlert, 1889. 

 Dalmania, Emmrich, 1844. 

 Dahnanites, Barrande, 1852. 

 Hausmannia, Hall & Clarke, 1888. 

 Somalops, Remele, 1884. 

 Malladaia, Oehlert, 1896. 



Metacanthus, Corda, 1847. 

 Monorakos, Schmidt, 1886. 

 Odontocephalns, Conrad, 1840. 

 Odontochile, Corda, 1847. 

 Phacops, Emmrich, 1839. 

 Fleur acanthus, Milne-Edwards, 1840'. 

 Fortlockia, McCoy, 1846. 

 Probolium, Oehlert, 1889. 

 Pterygometopus, Schmidt, 1881. 

 Somatrikelon, McMurtrie, 1819. 

 Synphoria, Clarke, 1894. 

 TrimeroGephalus, McCoy, 1849. 



Of the above names, PleuracantJms and CryphcBUS are both pre- 

 occupied, the former both by a genus of Coleoptera (Gray, 1832) 

 and by a genus of fishes (Agassiz, 1837), the latter by a genus of 

 Coleoptera (Klug, 1833). CrypJiiSus was founded on the American 

 species Cr. Boothi, Green, of which Ci: collitelus, Green, which 

 possesses a median terminal spine to the pygidium as well as the 

 five lateral pairs, was considered merely a variety by Hall.^ Corda, 

 in dealing with the similar European species C. arachnoides 

 (Hoeninghaus) and C. stelUfer, Burmeister, considered the presence 

 or absence of the terminal spine a feature of generic importance; and 

 accordingly put them in separate genera, which he called Asteropyge 

 and Metacanthus respectively. Salter - was the first to denounce the 

 artificiality and weakness of this division ; so that, as Gryplieeus is 

 not available as a generic or group name, Asteropyge must be used 

 as its designation. Kayser^ has endeavoured to subdivide Crypliaus 

 again into Corda's two sections. 



Though the type-species of Dalmania is D. caiidatus (Briinn.) 

 and that of Odontochile 0. Hausmanni (Brong.), (or as Barrande 

 declares D. Renssi, Barr.), yet it was early recognised that these 

 species were congeneric. Both Dahnnnia and Odontochile were 

 unfortunately preoccupied, the former by a genus of Diptera 

 (Robineau Desvoidy, 1830) and the latter iDy a genus of Coleoptera 

 (Odontocheila, Laporte, 1834), so that Barrande proposed the name 

 Dalmanites, which though often used in a very wide sense, yet must 

 hold good as the group - name of which the type - species is 

 D. caiidatus. Hall & Clarke* employed the name Dalmanites in 

 such a wide sense that they proposed, the name Hausmannia for the 

 sub-group containing the type-species ; but Oehlert ® considers it an 

 unnecessary duplicate name. 



Acaste must be considered as preoccupied, the name Acasta 

 having been given by Leach in 1811 to a genus of Cirripedes. 

 There is no strict synonym for this group, so that the name must be 



1 Hall & Clarke : op. cit., p. 45. 



2 Salter: Mem. Geol. Surv., dec. ii, 1849, art. 1, p. 8. 



3 Kayser: "Die Fauna alt. Dev. Ablag. Harzes," p. 33 (Abhandl. geol. spec. 

 Kart. Preuss., Bd. ii. Heft 4, 1878). 



* Hall & Clarke : op. cit., p. xxxi. 



5 Oehlert: Bull. Soc. Geol. France, ser. iii, vol. xvii (1889), p. 758. 



