190 BRITISH PALEOZOIC PHYLLOCARIDA. 



branch more or less from one another. On the antepenultimate they " con- 

 verge by running, in a curving course, towards the anterior outer embossed angles 

 of the segment, 1 or join others that do." 



The specimen came from a black limestone of the Coal-measures at Danville, 

 Illinois. Referred to "No. 14" bed of the Coal-measures of Vermilion County, 

 Illinois, in Bradley's ' Geology of Illinois,' vol. iv, pp. 224-7. 



18. Dithyeooaris carbonaeia, Meek and Worthen, 1870. Plate XXIX, figs. 5 a, b, 

 and 6. (Copied from M. and W., figs. 1 a and 1 b, op. cit. infra.) 



Dithyrocaris carbonarius, Meek and Worthen, 1870. Proceed. Acad. Nat. Sci. 



Philadelphia, vol. xxii, p. 55. 

 — — 1873. Geol. Surv. Illinois, vol. 



v (Geol. and Paleont.J, p. 618, 

 pi. xxxii, figs, la, 1 b. 

 — C. A. White, 1884. Thirteenth Eep. Dept. Geol. 



Nat. Hist. Indiana, p. 178, pi. xxxix, fig. 2. 

 (carbonaeia, fide J. P. Lesley), O. E. Hall, 1876. Proceed. 



Amer. Philos. Soc, vol. xvi, No. 6, p. 56. 

 carbonaeia, S. A. Miller, 1877. Pal. Fobs. America, p. 217; and 

 1889, North- Amer. Geol. and Paleont,, p. 545. 



— E., W., and J., 1887. Eep. Brit. Assoc, for 1886 



(1887), p. 63. 



— J. P. Lesley, 1889. Diet. Foss. Pennsylv., p. 212. 



— A. W. Vogdes, 1893. Bibliogr. Palaeoz. Crust., 



p. 382. 



Size 



•-In fig. 6 (M. and W.'s fig. 1 b, nat. size) ; ventral aspect : 

 \ Style (including head or caudal plate) 22 mm. long, and 4 mm. wide at 

 1 the top. 



^Stylets 22 mm. long when perfect, and 4 mm. wide. 

 Characters. — The proximal parts of a caudal trifid. The spines appear to 

 have been relatively short and thick. The style is bayonet-shaped and smooth ; 

 sectional areas are given with M. and W.'s fig. 1 a for the upper and lower portions. 

 The stylets are coarsely striate on the proximal moiety, with 5 — 7 costulge ; and 

 have only smooth mid-ribs on their distal halves. The style was probably rather 

 shorter than the stylets, but they are all broken at the tips. 



Prom the Middle Coal-measures at Danville, Illinois ; and the Coal-measures 

 of Warren County, Pennsylvania. 



1 Analogues of these radiate knobs may be seen in the abdominal segments of Ceratiocaris 

 Murchisoni, Bg. \</, pi. iii, ' Monogr. Brit. Pal. Phyll.,' pnrt i, 1888. 



