GimuH of JjOiner Il'lffcrh'-iy Oxfrdcf/da. — (J I rich. \\)\) 
acuminate or rounded. Y("ntral edge gently convex, occasionally 
straightened in tlu; middk;. Ilingement simple, the dorsal edge 
of the right valve; esp(;cinlly sorn(;vvliat thickened and in thecitntral 
portion slightly overlapping tlu; left valve. 
Tj'pe, Beecherello, airliuitd.^ n. sp. 
Some of the speci(!S al)out to \m descriljed under this generic 
name deviate rather widcdy from th(; one selected as tlu; type. 
Only one feature is common to them all — the anterior spine. 
The value of this character as an indication of true generic 
affinity may have been ov(!r estimatc^d, and it is tlK^refore possible 
that more than one generic group is represented. This is however 
a point that cannot as yet be d(!t(!rmined, since, without more 
material of these and otiier speci(!S that sooner or later is certain 
to be discovered, it is not possibh; to i^ick out with certainty the 
really diagnostic characters. 
H. ocafd, may s(!em the farthest removed from li. ciii'nniin^ but 
B. suhtumida is clearly an intermediate form, as is also B. rnsifdo. 
B. luivicuhi, and aiujiihirls^ however, difF(!r from all tlu; others in 
this, that the anterior spine is a jjrolongation of the dorsnl edge 
instead of the dorsal carina or of the anterior sloi>e. It is here, 
perhaps that another g(;nus is indicated. 
Respecting the position of Bcirhcnll'i I find myself (piit(! 
unable to arrive at any satisfactory conclusion. .Many of the 
Cypridinid^e it is true;, have an anterior spini; or hook, but here 
the resemljlance ceases. The thin shells of the Cypridae also are 
({uite different, though on(! form of ('iji>ils has been described as 
having a front spine ( (J. coral <j<r(i.^ Jones Geol. Mag. 1 888, p. 
?>'M'k fig. la-f), and B'urdla occasionally presents resemljlances. 
.\iid then the L( pi r<litiid(i\, a family that already includes many 
odd forms, does not, so far as I can s(;e, contain anything throw- 
ing light upon the question. At i)resent, therefore, I am obliged 
to \\cvi BcachfucWi as one of thost; groups of fossils, so frequently 
presented to the student of paleozoic paleontology, that battle tlu; 
most careful efforts of the; systematist to cla.ssify successfully. 
Beecherella carinata, n. sp. 
I'L.VTK II, FIOS. 1-4. 
Size: a large right valve; greatest length, :{. (»() nim. ; greatest 
hight,0.77 mm.; greatest thickness, 0.50 mm.; length of anterior 
spint; aV)out 0.G5 mm.; greatest h^ngth of valve at inner edge, 
2.!»0 mm. 
