BAT.] 



CRUSTACEA. 



533 



Bathyurellus, Billings, 1865, Pal. Foss, vol. 

 1, p. 262. [Ety. diminutive of Bathyu- 

 rus.] Form oblong, ovate; cephalic 

 shield convex, lunate; glabella conical 

 or pointed, without furrows; eyes lu- 

 nate; facial suture in front of the eye, 

 curving outward, then straight forward 

 or inward on approaching the margin 

 behind the eye, running outward sub- 

 parallel to the neck furrow, and cutting 

 the margin before reaching the outer 

 angle; thorax, nine segments; axis of 

 pygidium short, not strongly grooved, 

 side lobes with short ribs, and a broad, 

 smooth border all around, sometimes con- 

 cave. Type B. abruptus and B. nitidus. 

 abruptus, Billings, 1865, Pal. Foss., vol. 1, 



p. 263, Quebec Gr. or Up. Taconic. 

 brwileyi, Meek, see Asaphiscus bradleyi. 

 expansus, Billings, 1865, Pal. Foss., vol. 1, 



p. 318, Quebec Gr. or Up. Taconic. 

 formosus, Billings, 1865, Pal. Foss., vol. 1, 



p. 266, Quebec Gr. or Up. Taconic. 

 fraterhus, Billings, 1865, Pal. Foss., vol. 1, 



p. 267, Quebec Gr. or Up. Taconic. 

 litoreus, Billings, 1865, Pal. Foss., vol. 1, 



p. 320, Quebec Gr. or Up. Taconic. 

 marginatus, Billings, 1865, Pal. Foss., vol. 



1, p. 264^ Quebec Gr. or Up. T^nic. 

 nitidus, Billings, 1865, Pal. 

 Foss., vol. 1, p. 265, Que- 

 bec Gr. or Up. Taconic. 

 rarus, Billings, 1865, Pal. 

 Foss., vol. 1, p. 320, Que- 

 bec Gr. or Up. Taconic. 

 truncatm, Meek, 1873, Hay- 

 den's Geo. Sur. Terr., p. 

 465. Not satisfactorily FlQ ^"_ Ba _ 

 defined. thyuiellus ni- 



validus, Billings, 1865, Pal. tidus. 



Foss., vol. 1, p. 268, Quebec Gr. or Up. 

 Taconic. 

 wheeleri, Meek, see Asaphiscus wheeled. 

 Bathyuriscus, Meek, 

 1873, 6th Rep. 

 Hayden's U. S. 

 Geo. Sur. Terr., p. 

 484. [Ety. from 

 Bathyurus.~\ Ovate; 

 head semicircular ; 

 glabella straight or 

 slightly expanded 

 in front, three or 

 four pairs of fur- 

 rows ; eyes elon- 

 gate ; facial su- 

 tures cut the an- 

 terior margin of the head each side of 

 the greatest expansion of the glabella, 

 and extend obliquely inward to the an- 

 terior bases of the eyes ; encircling the 

 latter, they extend obliquely outward, 

 cutting the posterior margin so as to 

 leave a narrow, elongate lateral limb ; 

 thorax from 7 to 9 segments; axis 

 strong; pleural groove broad ; pygidium 

 semicircular, axis strong, and crossed 

 by several furrows which cross the 

 lateral lobes. Type B. haydeni. 



FIG. 972.— Bathyuriscus 

 productus. 



haydeni, Meek, 1873, (Bathyurus hay- 

 deni,) 6th Rep. Hayden's U. S. Geo. 

 Sur. Terr., p. 482, Up. Taconic. 



howelli. Walcott, 1886. Bull. U. S. Geo. 

 Sur. No. 30, p. 216. Up. Taconic. 



productus, Hall& Whitfield, 1877, (Ogygia 

 producta,) Geol. Expl. 40th Par., vol. 4, 

 p. 244, Up. Taconic. 

 Bathyurus, Billings, 1859, Can. Nat. and 

 Geo., vol. 4, p. 365. [Ety. bathys, deep ; 

 oura, tail.] Elliptical, sides straight ; 

 cephalic shield lunate, posterior angles 

 produced in spines ; glabella subquad- 

 rate, rounded anteriorly, convex, fur- 

 rows obscure, neck segment distinct; 

 eyes large, smooth, semilunar; facial 

 sutures curving forward anteriorly, and 

 posteriorly directed straight backward 

 from the eye, and then, abruptly curv- 

 ing outward, cut the cephalic shield 

 half-way to the genal angle ; nine tho- 

 racic segments, axial lobe narrower than 

 lateral lobes, and gradually tapering ; 

 pleurae furrowed ; pygidium smaller 

 than the head, segments closely united, 

 border flattened and smooth; hypo- 

 stoma not forked. Type B. extans. 



amplimarginatus, Billings, 1859, Can. Nat. 

 and Geo., vol. 4, p. 365, Calciferous Gr. 



angelini, Billings, 1859, Can. Nat. and 

 Geol., vol. 4, p. 468, Chazy Gr. 



arcuatus, Billings, 1865, Pal. Foss., vol. 1, 

 p. 205, Quebec Gr. or Up. Taconic. 



armatus, Billings, 1860, Can. Nat. and 

 Geo., vol. 5, p. 321, Quebec Gr. or Up. 

 Taconic. 



bituberculatus, Billings, 1860, Can. Nat. 

 and Geo., vol. 5, p. 321, Quebec Gr. or 

 Up. Taconic. 



breviceps, Billings, 1865, Pal. Foss., vol. 1, 

 p. 262, Quebec Gr. or Up. Taconic. 



capax, Billings, 1860, Can. Nat. and Geol., 

 vol. 5, p. 321, Quebec Gr. or Up. Taconic. 



caudatus, Billings, 1865, Pal. Foss., vol. 1, 

 p. 261, Quebec Gr. or Up. Taconic. 



conicus, Billings, 1859, Can. Nat. and 

 Geol., vol. 4, p. 366, Calciferous Gr. 



(?) congeneris, Walcott, 1885, Monogr. 

 U. S. Geo. Sur., vol. 8, p. 92, Quebec 

 Gr. or Up. Taconic. 



cordai, Billings, 1860, Can. Nat. and Geol., 

 vol. 5, p. 321, Calciferous Gr. 



crotaliformis, Dwight, 1884, Am. Jour. 

 Sci. and Arts, 3d ser., vol. 27, p. 253; 

 Calciferous Gr. 



cybele, Billings, 1859, Can. Ndt. and Geol., 

 vol. 4, p. 366, Calciferous Gr. 



dubius, Billings, 1860, Can. Nat. and 

 Geo., vol. 5, p. 321, Quebec Gr. or Up. 

 Taconic. 



extans, Hall, 1847, (Asaphus (?) extans,) 

 Pal. N. Y., vol. 1, p. 228, Lower Tren- 

 ton Gr. 



gregarius, Billings, 1865, Pal. Foss., vol. 

 1, p. 363, Up. Taconic. 



haydeni, see Bathyuriscus haydeni. 



longispinus, Walcott, 1876, 28th Rep. 

 N. Y. St. Mus. Nat. Hist., p. 94, Black 

 River and Trenton Grs. 



35 



