ON THE FOSSIL PHTLLOPODA OF THE PALEOZOIC KOCKS. 63 



namely, the Upper and the Lower Carboniferous (especially in the latter), 

 and the Devonian, of Europe, the British Isles, and North America. 

 The following list indicates the geological horizons and the localities. 

 There are two species from the Coal-measures of the United States, 

 twelve from the Lower- Carboniferous of the Continent and British Isles 

 (chiefly from Lanarkshire in Scotland), and six Devonian species. 



DiTHTROCARis, Scouler, 1843. 



Argas, Scouler, ' Records of General Science ' (Thomson's), vol. i 

 1835, p. 136. 



Dithyrocaris, Scouler in Portlock's ' Geol. Report Londonderry, &c ' 

 1843, p. 313. 



Bithyrocaris, M'Coy, ' Ann. M. N. H.' ser. 2, vol. iv. 1849, p. 395. 



Dithyrocaris, Morris, ' Catal. Brit. Foss.,' 1854, p. 107. 



Bithyrocaris, Woodward and Etheridge, 1870, 1873, 1879, &c. 



Bithyrocaris and Argus \_Argas'], Packard, ' Monogr. Phyll. Americ.,' 

 1883, p. 451. 



I. Upper- Carboniferous Species of Dithyrocaris. 



1. Bithyrocaris carbonaria, M. and W., 1873. 



Bithyrocaris (?) carbonarius. Meek and Worthen, ' Geol. Survey of 

 Illinois,' vol. v. (Geology and Palaeontology), 1873, p. 618, pi. 32, 

 f. la, lb. 



B. carbonaria, Miller, ' Catal. Pal. Foss. Amer.,' 1877, p, 217. 



Carboniferous. — Middle Coal-measures, Danville, Illinois. 



2. Bachura [probably Bithyrocaris'] venosa, Scudder, 1878, ' Proceed. 

 Boston Soc. Nat. Hist.,' vol. xix. pp. 296, 2^7, pi. 9, f. 3, 3a ; Packard, 

 ' Monogr. N.-Amer. Phyll.,' 1883, p. 452. 



Carboniferous. — Coal-measures ; Danville, Illinois. 



II. — Lower-Carboniferous Species of Dithyrocaris. 



1. Bithyrocaris tricornis, Scouler, 1835. 



Argas tricornis, Scouler, ' Records of General Science ' (Thomson's), 



vol. i. 1835, pp. 137, 141, fig. 2. 

 Bithyrocaris tricornis, Morris, ' Cat. Brit. Foss ' 1854, p. 107. 

 B. tricornis, W. and E.. 'Mem. Geol. Surv. Scotl, Expl. Sheet 23,' 



lh73, p. 99 ; ' Geol. Mag.,' 1873, pp. 483, 486, pi. 16, f. 2 and 3. 

 Lower-Carboniferous. — One mile south-east of Paisley, Renfrewshire ; 



East Kilbride, Lanarkshire. 



2. Bithyrocaris testudinea, Scouler, 1835. 



Argas testudineus, Scouler, ' Records of General Science ' (Thomson's), 



vol. i. 1835, pp. 137, 141, f. 3. 

 Bithyrocaris Scouleri, M'Coy, ' Syn. Carb. Foss. Irel.,' 1844, p. 163, 



pi. 23, f. 2. 

 B. testudineus, Morris, ' Catal. Brit. Foss.,' 1854, p. 107. 

 D. testudineus, W. and B., 'Mem. Geol. Surv. Scotl, Expl. Sheet 



23,' 1873, .p. 98 ; ' Geol. Mag.,' 1873, p. 482, pi, 16, f. 1. 

 B. testudineus, Etheridge, ' Q. J. G. S.,' xxxv. 1879, p. 465, pi. 23, 



f . 1 

 Lower-Carbo7iiferous. — Near Paisley, Renfrewshire ; East Kilbride, 



Lanarkshire ; New Castleton, Roxburghshire. 



3. Dithyrocaris Colei, Portlock, 1843. 



' Geol. Report Londonderry, &c.,' 1843, pp. 314, 565, 570, &c., pi. 1 2. 



