364 H. Woodward — Anthrapalcemon from M. Coal-measures. 



and ridged. Subjoined is a list of American species referred to the 

 genus Anthrapalcemon : — 



Anthrapalcemon Hilliana, Dawson, 1877. Geol. Mag-., Dec. II, Vol. IV, p. 56, 



Fig. 1. Coal-measures: South Joggins, Nova 



Scotia. 

 ,, ,, Dawson, 1878. Acadian Geology, Supp., p. 55, 



fig. 10. Coal-measures : South Joggins, Nova 



Scotia. 

 ,, gracilis, Meek & Worthen, 1865. Proc. Acad. Nat. Sci. 



Phil., vol. xvii, p. 50. Coal-measures : Mazon 



Creek, Grundy Co., Illinois. 

 Meek & Worthen, 1866. Geol. Surv. Illinois, vol. ii, 



p. 407, pi. xxxii, figs. 4a-c ; vol. iii, p. 554, figs, a, b. 

 White, 1884. Thirteenth Eeport Dept. Geol. Nat. 



Hist. Indiana, p. 180, pi. xxxviii, figs. 8, 9. 

 ,, ,, Packard, 1885. American Naturalist, vol. xix, 



p. 880. 

 ,, ,, Packard, 1886. Mem. Nat. Acad. Sci., vol. iii, 



p. 135, pi. iv, figs. 1-3, 5, 6 ; pi. vii, figs. 3-6. 



In 1905 I added a species of Anthrapalcemon (A. serratus) from the 

 Lower Coal-measures, Colne, Lancashire (see Geol. Mag., Dec. Y, 

 Yol. II, pp. 438-9, Fig. 1), and another (either Pygocephalus or 

 Anthrapalcemon (?) Parlceri, H. Woodw.) from the Coal-measures of 

 Sparth, near Rochdale (see Geol. Mag., Dec. Y, Yol. IY, p. 406, Fig. 2, 

 1907). I also gave a fuller account in 1907 (op. cit., pp. 400-7) of 

 Pygocephalus, and figured and described the marsupial plates in the 

 female of P. Cooperi (op. cit., Plate XYIII), not heretofore observed 

 in a fossil Crustacean. 



I am indebted to Mr. Fred Holt, of Rochdale, for the opportunity 

 to figure and describe one of the largest specimens of an Anthrapalcemon 

 from the Coal-measures I have yet seen. It was obtained from 

 a concretion of clay-ironstone, on the reverse side of which several 

 casts of Lamellibranch shells (Carlonicola, etc.) are exposed. Notwith- 

 standing some irregular fractures the nodule exhibits on its upper 

 surface the cephalo-thoracic shield of a Palinuroid, the contour of 

 which, as well as the ornament on its dorsal region, is very well 

 preserved (a thin crust-like cover represents the obverse of the cast 

 which originally concealed the carapace from view). 



Dimensions. Length of carapace, 42 mm. ; greatest middle breadth, 

 36 mm. ; breadth upon the front border of shield, 25 mm. ; at posterior 

 border, 20 mm. ; the posterior border is strongly arched, rising 6 mm. 

 at the centre on the dorsal line. The lateral borders are moderately 

 expanded outwards, and the margin on either side is sharply serrated 

 along the anterior half (Fig. lc), ending in a prominent spine on the 

 hitero- anterior border. Inside the latero-anterior spines the frontal 

 border is nearly straight or but slightly curved towards the rostrum, 

 which is prominent and had one or more serrations on its basal portion. 

 The dorsal ridge is prominent for 26 mm., when it is crossed by and 

 subsides into the cervical furrow, which is strongly arched for 8 mm. 

 on either side the dorsal line ; it then bifurcates sharply anteriorly 

 towards a submedian spine, and posteriorly to join a longitudinal 

 furrow running obliquely to the posterior margin. The dorsal region 

 of the carapace between these oblique longitudinal lines is ornamented 



