BAT. — BOL.] 



CRUSTACEA. 



705 



terior half of the more or less convex 

 dorsal side ; the edges of the valves in 

 this portion of the back are smooth, 

 and resemble a pair of thick lips ; 

 edges of both valves thick and smooth 

 all around, that of tbe right valve 

 much the heavier; a sharply defined, 

 narrow or rounded umbilical pit; sur- 

 face striate. Type B. punctostriata, 

 which, with B. punctostriata var. curta 

 and B. pulchella, are described at the 

 same place from the Up. Held, or 

 Ham. Gr. 



Bathyurellus, Whitfield, 1890. Bull. Am. 

 Mus. Nat. Hist., vol. 3, p. 38, Up. 

 Taconic or Calciferous. 



Bathyuriscus dawsoni, Walcott, 1888, 

 Proc. U. S. Nat. Mus., p. 446, Up. 

 Taconic. 



Bathyurus seelyi, refer to Bolbocephalus 

 seelyi. 



Beecherella, Ulricb, 1891, Am. 

 Geo., vol. 8, p. 198. [Ety. proper 

 name.) Carapace small, elon- 

 gate, boat - shaped to ovate, 

 moderately convex, more or 

 less inequivalve ; dorsal mar- 

 gin varying from nearly straight 

 to strongly convex ; back some- 

 times flattened, with a sharply 

 defined carina on one or both 

 valves, giving them a triangu- 

 lar shape in cross sections ; in 

 other cases the dorsal slope is 

 convex ; antero-dorsal extremity 

 acuminate, often drawn out 

 into a long spine ; spine strong 

 est on the right valve, some- 

 times absent on the left ; pos- 

 terior extremity acuminate or 

 rounded; ventral edge convex 

 or straightened in the middle ; 

 hingement simple, dorsal edge 

 of right valve thickened, and 

 in the central part overlapping 

 the left valve. Type B. carinata, 

 described at the same place, FlG 1262 

 from the Low. Held. Gr., with 

 B. cristata, B. angulata, B. navi- 

 cula, B. ovata, B. subtumida, and B. 

 subtuwida var. intermedia, from the 

 same rocks. 



Beyrichia ciliata, refer to Ctenobolbina 



ciliata. 



clavigera and B. clavigera var. clavifracta, 



Jones, 1891, Cont. to Micro-Pal., p. 65, 



Chazy Gr. ; and B. quadrifida, p. 66, 



Trenton Gr. ; and B. tuberculata var. 



strictispiralis, p. 77, Up. Sil. Also B. 



clarkei, 1890, Quar: Jour. Geo. Soc, 



vol. 46, p. 17, Low. Held. Gr., ; and B. 



diftisa, p. 546, Anticosti Gr. ; and B. 



halli, p. 15, Waterlime Gr. ; and B. 



hamiltonensis, p. 19, Ham. Gr. ; and 



B. kalmodini, p. 538, Ham. Gr., and 



' B. subquadrata, p. 537, Corniferous Gr. 



duryi, refer to Ctenobolbina duryi. 



lyoni, Ulrich, 1890, Jour. Cin. Soc. Nat. 



Hist., vol. 13, p. 190, Up. Held, or 



Ham. Gr. ; also B. tricollina, Ham. Gr. ; 

 and B. radiata var. cestriensis and B. 

 simulatrix, pp. 204, 205, Kaskaskia Gr. 



richardsoni, refer to Depranella richard- 

 soni. 



symmetrica, refer to Bollia symmetrica. 



tuberculata, Klceden, 1834, (Battus tuber- 

 culatus,) Verst. d. Mark Brandenburg, 

 p. 115, Up. Sil. 

 Bolbocephalus, Whitfield, 1890, Bull. Am. 

 Mus. Nat. Hist., vol. 3, p. 36. [Ety. 

 bolbos, bulb; kephale, head.] Head 

 large, semicircular, including the mov- 

 able cheeks ; glabella proportionally 

 large, bulbous or subspherical, ex- 

 panded in front of the eyes, and marked 

 by a single, very indistinct furrow 

 near the posterior ; fixed cheeks 

 narrow ; eyes large, semicircular, ele- 

 vated ; lateral limbs narrow from froat 

 posteriorly ; frontal limb linear ; facial 



Beecherella carinata. Right valve, interior and 

 dorsal views of same. Maguitied 20 diameters. 



suture cutting the posterior margin 

 within the genal angle behind, and 

 passing closely around the glabellar 

 lobe in front; movable cheeks trian- 

 gular, marginal, spined ; pygidium semi- 

 circular, lobed, and transversely fur- 

 rowed. Type B. seelyi. 



seelyi, Whitfield, 1886, (Bathyurus seelyi,) 

 Bull. Am. Mus. Nat. Hist , vol. 1, p. 339, 

 Calciferous Gr. 



truncatus, Whitfield, 1890, Bull. Am. 

 Mus. Nat. Hist., vol. 3, p. 37, Calcifer- 

 ous Gr. 

 Bollia Jones & Holl, 1886, Ann. and Mag. 

 Nat. Hist., ser. 5, vol. 17, p. 360. [Ety. 

 proper name.] Valves oblong, with 

 rounded and nearly equal ends ; straight 

 on the back, more or less outcurved on 

 the ventral edge ; surface punctate and 

 bearing a lobular elevation on each side 



