304 GEOLOGICAL SURVEY OF THE TERRITORIES. 
Synopsis of the species. 
Shell large, ion beaks close to anterior end and very small; second an- 
tenn 13- and 15- IOUINC CC Lc ic NaN: NI eS (ee ee B. californica. 
Like californica, but with more prominent beaks, dorsal edge sloping 
directly down to the posterior end ..-. ..........-.--- FE. newcombii 
Shell long and narrow; beaks small, situated very near anterior end; 
telson armed with small fine teeth ; hands of male short and thick ; 
flagella 5- and 14 jomteds ses sue pee ae weer ene HH. compleximanus 
Shell more swollen; beaks larger, and farther from anterior end; dor- 
sal edge short, suddenly sloping to posterior end; flagella 17- and 
16-jointed ; telson with larger teeth interpolated in the smaller 
OTE Se Base DRS EET hs ent cle eta tome eteeena eran CALEY eT Be LOMO EE. mexicana 
Shell still more globose than in LH. mexicana; beaks more prominent in 
anterior third of shell; flagella 17- and 16-jointed.......... EE. morsei 
Shell globose; beaks large and prominent, more central than in pre- 
ceding species; flagella 14- and 15-jointed.............. LH. belfraget 
Shell very large, thick, globose, swollen; beaks larger and fuller, cen- 
tral; with more numerous lines of growth than any preceding spe- 
cies flagella dy andilG7ombved ns. see see ese oc ee eee E. jonesti 
ESTHERIA CALIFORNICA Packard. 
Plate IV, figs. 1-5. 
Estheria californica Packard, Sixth Rep. Peab. Acad. Se., Salem, 55, 1874. Hayden’s 
U. §. Geol. Surv. Terr. for 1873, 618, 1574. Lenz, Kstheria californica, &e., 
Labeok, Aug. 5, 1876. 
Shell remarkably thin, so that at first sight it might be mistaken for a 
Limnadia; in outline subtriangular; the umbones unusually small, 
very oblique, EUS aa eit much nearer than usual to the 
EE Ee anterior edge; dor- 
saledge convex, curv- 
ing gradually to the 
rounded posterior 
end. Highteen to . 
thirty-five lines of 
growth. Shell very 
smooth, shining, with 
very fine granulations 
too numerous to be 
counted with a two- 
thirds-of-an-inch trip, 
let; when more highly 
magnified they ap- 
pear as in Plate 
XXIV, fig. 5. First 
Fic. 7.—Estheria californica. antenns rather slen- 
der, the papille, however, not very wellmarked. Second antennze with 
the upper flagellum 13-jointed, and much shorter than thelower, whichis 
15-jointed. Twenty- two pairs ‘of feet. The gillis rathersmall and short; 
the upper division of the flabellum very long and slender, reaching to 
the back of the animal; the lower one acutely trianglar; the sixth en- 
dite is a little longer than the lower flabellum, and is broader in the third 
than in the first pair of limbs; the fifth endites are slender, long, and 
narrow, finger-shaped. The telson i is armed above with numerous fine 
