North Amer'ican Palseozoic Crustacea. 



11 



tumifrons, Hall & Whitfield, 1875 ; Pal. Ohio, vol. 2, p. 102, pi. 4, fig. 8. 

 tumifrons. Miller, 1874 ; Cincinnati Quart. .Jour. Sci., vol. 1, p. 119. 

 venusta, Billings, 1866 ; Catalogue Sil. Foss. Anticosti, p. 68. 

 Carbonia, Jones & Kirby, 1879 ; Annals & Mag. Nat. Hist., 5th series, London, 



vol. 4, p. 28. 

 Diagnosis. — Subovate or elongate in outline, with the dorsal margin 



rounded and the ventral margin nearly straight ; valves convex, the 



right rather the larger and overlapping the left ventrally ; hinge 



simple ; muscle-spot circular ; surface smooth, sometimes pitted. 

 ? Bairdioides (?), Jones & Kirkby, 1884; Geol. Mag., 5th series, London, 



vol. 1, p. 358, pi. 12, figs. 8a-d. Carboniferous. 



Bairdia sp. ? Dawson, 1868 ; Acadian Geology, p. 206, fig. 48 a? 

 Cythere? (Carbonia), Bairdioides, Jones & Kirkby, 1879; Annals & Mag. Nat. 



Hist., 5th series, London, vol. 4, p. 38, pi. 3, figs. 24, 27. 

 Carbonia? Bairdoides ? Jones & Kirkby, 1884; Geol. Mag., Dec. 3, p. 358, 



pi. 12, figs. 8a-d. 

 ?elongata, Jones & Kirkby, 1884; Annals & Mag. Nat. Hist., 5th series, 



London, vol. 1, p. 361, pi. 12, fig. 10. Carboniferous. 



? elongata, Jones & Kirkby, 1884; Geol. Mag., Dec. 3, p. 361, pi. 12, fig. 10. 

 fabulina, Jones & Kirkby, 1879; Annals & Mag. Nat. Hist., 5th series, 



London, vol. 4, p. 31, pi. 2, figs. 1-9 ; and var. humilis, id., figs. 11-14. 

 fabulina, Jones, 1889 ; Geol. Mag., Dec. 3, vol. 6, p. 270, figs. 1-4. 

 Cyiherella injlata, Dawson, 1868; Acadian Geology, p. 206, fig. 48 b. 



fabulina, Jones & Kirkby, 1884; Geol. Mag., Dec. 3, vol. 1, p. 358, pi. 12, 



figs. 9 a-e. 

 Ceratiocaris, McCoy, 1849 ; Annals & Mag. Nat. Hist., London, vol. 4, p. 412. 

 Gen. Cliar. — Carapace bivalve, the dorsal line simply 



angulated (? undivided), with a slight furrow be- 

 neath it on each side ; sides semielliptical, much 



elongated from before backwards, evenly convex, 



ventral margin gently convex, posterior end ab- 

 ruptly truncated obliquely ; on each side near the 



anterior end considerably below the hinge-line is 



an ocular (?) spot sometimes raised and distinct, 



in some species flat ; surface marked with fine, 



imbricated strife, obliquely longitudinal. (McCoy, 



Contrib. Pal., p. 151.) 

 aculeatus. Hall, 1859 ; Pal. New York, vol. 3, p. 422*, 



pi. 80 a, fig. 10. Waterlime. 



acuminatus. Hall, 1859 ; Pal. New York, vol. 3, 



p. 422*, pi. 84, fig. 6. Waterlime. 



acuminatus, Pohlman, 1886 ; Bull. Buffalo Soc. Nat. 



Sci., vol. 5, p. 28, pi. 3, fig. 2. 

 armatus. Hall, 1863; see Echinocaris punctata. 

 Beecheri, Clarke, 1881 ; Bull. U. S. Geol. Survey, 



No. 16, p. 44, pi. 2, fig. 1. Devonian. 



