196 F. R. Cowper Heed — On Brachymefo2)us. 



trilobites with spinose and non-spinose representatives. The fewer 

 number of segments in the pygidium and the raised spinigerous 

 border separate it from all the European forms. The genus or 

 subgenus JPhaetonides, as now understood, is partly distinguished 

 for analogous reasons from the typical Froetus ; and it seems open 

 to question whether the European species of Brachymetopus should 

 not be regarded as constituting a distinct group or subgenus, for 

 which the name Brachymetopina may be suggested. Oehlert,' in his 

 review of the genus Brachymetopus and its allies, does not mention 

 any species with a spinigerous margin to the pygidium ; and 

 Claypole * was convinced that with the single possible exception 

 of FMllipsia lodiensis, Meek, and Dalmanites (?) CuyaTiogm, Claypole 

 (see below), every Carboniferous trilobite on either side of the 

 Atlantic possessed a pj'^gidium with a definite even outline. Von 

 Moller ^ compared the Australian species Br. Strzeleckii with Eussian 

 forms, but in his description ascribes to it too many pygidial segments. 

 It is worthy of remark that he figures (op. cit., t. ii, fig. 32) a head- 

 shield (doubtfully attributed to Br. ouralicus) which shows the 

 circle of tubercles round the eyes, the pair of large tubercles in 

 front of the glabella, and one median tubercle on the glabella, which 

 are features well marked in Br. Strzelechii. 



It is, however, specially interesting to find in the Waverly Group 

 (Carboniferous) of North America members of the genus Brachymetopus 

 with spinigerous pygidia like the Australian species. Such are 

 Br. lodiensis, Meek,* from the Cuyahoga Shales of Ohio, of which 

 Herrick ^ expresses a doubt whether it is a true Brachymetopus ; 

 Br. spinosus, Herrick,*^ and probably Br. immaturus, Herrick," and 

 Br. occidentalis,^ Herrick, the three latter of which were referred 

 by Herrick to the genus Fhaetonides.^ There is also £r. armatus, 

 Vogdes,^" from the Waverly of Missouri, with a single pair of spines, 

 and Br. Cuyahogce, Claypole, which according to Vogdes (op. cit.) i& 

 only an imperfectly preserved example of Brachymetopus, and not 

 one of the Phacopidse. 



As McCoy's figures of Br. Strzelechii are not very clear, and 

 Plews' ^^ figure is misleading, a restoration, based on the types, is 

 here given of the head-shield and pygidium. (Figs. 1, 2, p. 194.) 



The species has been recorded by Etheridge, jun. (Oat. Austr. 

 Foss,, Camb. 1878, p. 41), from Dunvegan, Burragood, and Glen 

 William, all in New South Wales. 



1 Oelilert: Bull. Soc. Et. Sclent. Angers, 1885, p. 10 (extract). 



2 Mon. Brit. Carb. Trilob. (Palfeont. Soc, 1884), p. 77. 



3 Von Moller: Bull. Soc. Imp. Nat. Moscou, xl (1867), p. 145. 



* Eep. Geol. Sui'v. Ohio, vol. ii, Geol. and Palaeont., 1875, p. 323, pi. xyiii, fig. 3 

 [Phillipsia [Griffithides?) lodiensis, Meek]. 



5 Herrick: Bull. Denisou Univ., vol. ii, pt. 1 (1887), p. 57. 



6 Ibid., vol. iv (1889), p. 58, pi. i, figs. 4, 5; and Bull. Geol. Soc. Amer., 

 vol. ii (1891), p. 42, pi. i, fig. 13. 



7 Ibid., vol. iv (1889), p. 59, pi. i, figs. 9-15. - 



8 Ibid., p. 57, pi. i, figs. 10«, b. 



9 Vogdes: Bibliogr. Pakcoz. Crust. (Occas. Papers Calif . Acad. Sc), 1893, p. 284.. 



10 Vogdes: Traus. St. Louis Acad. Sc, vol. v (1892), p. 617, pi. xv, figs. 4, 5. 



11 Plews: Trans. N. Engl. Instit. Min. Engin., vol. vi, p. 34, pi. iv. 



