548 



CRUSTACEA. 



[EUR. 



row; lateral lobes wide, flattened on 

 the margins; segments defined by lin- 

 ear ridges, which are produced beyond 

 the flattened borders in curved mucro- 

 nate spines; telson subtrigonal, gradu- 

 ally tapering. Tvpe E. dame. 



colletti, White, 1884, 13th Rep. Ind. 'Geo. 

 Sur. Nat. Hist., p. 172, Coal Meas. 



dame, Meek & Worthen, 1865, (Bellinu- 

 rus danae,) Proc. Acad. Nat. Sci. Phil., 

 p. 43, and Geo. Sur. 111., vol. 2, p. 395, 

 Coal Meas. 



Fig. 1007.— Enproops danse. e, Eyes ; p, pits ; 

 », node. 



longispina, Packard, 1885, Am. Naturalist, 

 vol. 19, p. 291, Coal Meas. 



Ecryptekeli.a, Matthew, 1888, Trans. Roy. 

 Soc. Can., p. HO. [VAy. diminutive of 

 Eurypferw.] Minute ; body ovate elon- 

 gate, obscurely divided into three re- 

 gions, and faintly trilobed ; head sub- 

 triangular, rounded at the outer corners, 

 emarginate behind, seemingly com- 

 posed of three anchylosed segments; 

 thorax subquadrate, four segments, 

 first one with a median ridge ; abdo- 

 men elongately triangular, several seg- 

 ments, produced in a long, flexible tail ; 

 surface tuberculated. Type E, ornata. 

 ornata, Matthew, 1888, Trans. Roy. Soc. 

 Can., p. 60, Lower Devonian. 



Eurypterus, DeKay, 1825, Ann. Lye. Nat. 

 Hist. N. Y.,vol. 1, p. 375. [Ety. euros, 

 breadth ; pteron, wing.] Body ovate-lance- 

 olate, gradually attenuate behind, termi- 

 nating in a spiniform tail ; carapace on 

 the upper side entire ; eyes two dis- 

 tant, sessile, within the margin of the 

 carapace, two simple oculiform tuber- 

 cles or cornea? situated subcentrally ; 

 thoracic and caudal portions composed 

 of thirteen joints, the first narrow and 

 the last prolonged in a triangular 

 spine, with serrated edges ; the first two 

 articulations are anchylosed on the lower 

 side, and from the central part a loco- 

 motive appendage is directed backward 

 to the 3d or 4th articulation, terminat- 

 ing in two slender processes ; mouth 



central, beneath the carapace, sur- 

 rounded by four pairs of jointed feet 

 and a fifth larger pair ; the three anterior 

 pairs are similar; several joints bear a 

 small articulating spine at the distal 

 extremities, and the terminal joint 

 consists of a spine ; the fourth pair is 

 longer, more slender, without spines, 

 except on the terminal joint ; the fifth 

 pair are natatory, longer, more dilated, 

 and placed beneath the posterior part 

 of the carapace, basal joints composed 

 of broad rhomboidal plates covering the 

 posterior part of the carapace, over the 

 inner edges of which there is a longitu- 

 dinally ovate plate, at the anterior sin- 

 uate margin of which is the entrance 

 to the mouth. Type E. remipes. 



beecheri, Hall, 1884, Geo. Sur. Pa. PPP, 

 p. 30, Chemung Gr. 



boylei, Whiteaves, 1884, Pal. Foss., vol. 3, 

 p. 42, Guelph Gr. 



dekayi, Hall, 1859, Pal. N. Y., vol. 3, p. 

 411, Waterllme Gr. 



eriensis, Whitfield, 1882, Ann. N. Y. 

 Acad. Sci., vol. 2, p. 196, Low. Held. Gr. 



giganteus, Pohlman, 1882, Bull. Buff. Soc. 

 Nat, Sci., vol. 4, p. 41, Waterlime Gr. 



grandis, Grote & Pitt, 1875, (Eusarcus 

 grandis,) Bull. Buff. Soc. Nat. Hist., 

 vol. 3, p. 17, Waterlime Gr. 



lacustris, Harlan, 1834, Trans. Geo. Soc. 

 Penn., vol. 1, p. 98, and Pal. N. Y., vol. 

 3, p. 407, Waterlime (Jr. 



lacustris var. robustus, Hall, 1859, Pal 

 N. Y., vol. 3, p. 410, Waterlime (Jr. 



mazonensis, Meek & Worthen, 1868, Am. 

 Jour. Sci., vol. 46, p. 21, and Geo. Sur 

 111., vol. 3, p. 544, Coal Meas. 



micropthalmus, Hall, 1859, Pal. N. Y., 

 vol. 3, p. 407, Low. Held. Gr. 



pachychirus, Hall, 1859, Pal. N. Y., vol. 

 3, p. 412, Waterlime Gr. 



pennsylvanicus, Hall, 1877, Proc. Am. 

 Phil. Soc, p. 621, Carboniferous. 



potens, Hall, 1884, Geo. Sur. Pa. PPP, p. 

 37, Carboniferous. 



prominens, Hall, 1884, Proc. Am. Ass. 

 Sci., vol. 33, p. 420, and Pal. N. Y., vol. 

 7, p. 137, Clin- 

 ton Gr. 



pulicaris, Salter, 

 1863, Quar. 

 Jour. Geo. 

 Soc, vol. 19, 

 p. 78, and 

 Acad. Geol., 

 p. 523, Up. 

 Devonian. 



p u s t u 1 os u s , 



Hall, 1859, 



Pal. N. Y., 



vol. 3, p. 413, 



W a t e r 1 ime 



Q r Fig. 1008.— Eurypterus rem- 



rem'inps De- lpes -. Dla g ram of smal1 

 rem l p e s , ue 8pe cimeu. 



Kay, 1825, 



Ann. Lye Nat. Hist. N. Y., p. 375, and 



Pal. N. Y., vol. 3, p. 404, Waterlime Gr. 



*>., 



