UO. — MEG.] 



CRUSTACEA. 



555 



Fig. 1026.— Lichas 

 trentonensis. 



pustulosus, Hall, 1859, Pal. N. Y., vol. 3, 

 p. 366, Low. Held. Gr. 



superbus, Billings, 

 1875, Can. Nat. and 

 Geol., vol. 7, p. 239, 

 Up. Held. Gr. 

 trentonensis, Conrad, 

 1842, (Asaphus tren- 

 tonensis,) Jour. 

 Acad. Nat. Sci., vol. 

 8, p. 277, and Pal. 

 N. Y., vol. 1, p. 235, 

 Black Riv. and Tren- 

 ton Grs. 

 Liostracus, Angelin, 

 1852, Palseontologica 

 Scandinavica, p. 23. 

 [Ety. leiostrakos, 

 smooth-she lied.] 

 Body elongate ; test smooth or with mi- 

 croscopic punctures; glabella elevated, 

 furrows faint ; dorsal furrow faint in 

 front; fixed cheek arched downward 

 at the sides ; front 

 limb concave ; .occipi- 

 tal ring aculeate ; head 

 at the genal angle 

 rounded ; ends of the 

 pleurae of the thorax 

 rounded; pygidium 

 minute, having few 

 segments. Type L. ac- 

 uleatus. 

 aurora, Hartt, 1868, (Con 

 ocephalites aurora, 

 Acad. Geol., p. 653, St. FlG . I02 7.-Liostra- 

 John Gr. cus aculeatus. 



linnarsoni, Brogger, 1878, 

 Paradoxides skifrene vid Krekling, p. 

 47, St. John Gr. 

 linnarsoni var. alata, Matthew, 1887, 

 Trans. Roy. Soc. Can., p. 147, St. 

 John Gr. 

 neglectus, Hartt, 1868, (Conocephalites 

 neglectus,) Acad. Geol., p. 652, St. John 

 Gr. Probably a syn. for L. tener. 

 ouangondianus, Hartt, 1868, (Conocepha- 

 lites ouangondianus,) Acad. Geol., p. 

 648, St. John Gr. 

 ouangondianus var. gibbus, Matthew, 

 1887, Trans. Roy. Soc. Can., p. 140, St. 

 John Gr. 

 ouangondianus var. immarginata, Mat- 

 thew, 1887, Trans. Roy. Soc. Can., p. 139, 

 St. John Gr. 

 ouangondianus var. planus, Matthew, 

 1887, Trans. Roy. Soc. Can., p. 140, St. 

 John Gr. 

 quadratus, Hartt, 1868, (Conocephalites 

 quadratus,) Acad. Geol., p. 654, St. 

 John Gr. 

 tener, Hartt, 1868, (Conocephalites tener,) 

 Acad. Geol., p. 652, St. John Gr. 

 IAsgocaris, Clarke, syn. for Spathiocaris. 



lutheri, see Spathiocaris lutheri. 



Lonchocephalus, Owen, 1852, Geo. Wis., 



Iowa, and Minn., p. 575. [Ety. longus, 



long ; kephale, head.] Cephalic shield, 



having a wide frontal limb ; posterior 



angle of each cheek terminating in a 

 spine ; glabella short, subquadrate, or 

 truncato-conical, highly arched; two or 

 three obscure furrows on each side ; 

 base projected backward, in a spine of 

 greater or less length, in the median 

 line, over the thoracic segments ; facial 

 sutures cut the anterior margin in front 

 of the eyes, and gently curve outward 

 and then inward to the anterior angles 

 of the palpebral lobes; thence curving 

 to the base of the eyes, they are di- 

 rected backward and slightly outward 

 to the posterior margin ; pygidium sup- 

 posed to be semilunar, with little or no 

 border, and having four segments in 

 the axial lobe. Type L. chippewensis. 

 chippewe nsis, 

 Owen, 1852, 

 Geo. Wis., Iowa, 

 and Minn., p. 

 576, Potsdam 

 Gr. 

 hamulus, Owen, 

 1852, Geo. Wis., 

 Iowa, and Fig. 1028.— Lonchoceph- 

 Minn., p. 576, alus chippewensis. 

 Potsdam Gr. 

 wisconsinensis, Owen, 1852, Geo. Wis., 

 Iowa, and Minn., p. 576, and 16th Rep. 

 N. Y. St. Mus. Nat. Hist., p. 146, Pots- 

 dam Gr. 

 Loganellus, Devine, 1863, Can. Nat. and 

 Geo., vol. 8, p. 95. [Ety. proper name.] 

 General form ovate; cephalic shield 

 lunate ; glabella convex, conical, two or 

 three oblique furrows on each side ; 

 facial suture behind the eye curving 

 outward, and cutting the posterior mar- 

 gin inside the angle and in front of the 

 eye, curving outward to the frontal 

 margin; thorax broad, side lobes flat, 

 pleurae about 

 twelve ; groove 

 running along the 

 middle nearly to 

 the extremities ; 

 pygidium with a 

 well-defined axis, 

 side lobes de- 

 pressed, and with 

 four to six ribs ; 

 distinguished from 

 Olenus by having 

 the facial suture 

 curved outward in 

 front of the eye. 

 Type L. quebecensis. This is one of 

 the forms often referred to Conocoryphe 

 or to Ptychoparia, but the genus may 

 be worth preserving, 

 quebecensis, Devine, 1863, Can. Nat. and 

 Geo., vol. 8, p. 95, Quebec Gr. or Up. 

 Taconic. 

 Megalaspis, Angelin, 1852, Palseontologia 

 Scandinavica. [Ety. megale, great ; aspis, 

 shield.] Body subelliptical ; cephalic 

 shield obtusely pointed in front, 

 genal angles spined ; glabella convex, 



Fig. 1029.— Longanel- 

 lus quebeceusis. 



