140 
ACTIN’ OPTEKYGII. 
Each pectoral fin with about 12 rays, the longest not reaching 
pelvic pair, which arises nearly midway between the pectora 9 
the anal, just in advance of the origin of the dorsal; ( * or ' stt , Q { 
deeper than long, with 11 or 12 rays, arising at the hinder en 
the anterior third of the back ; anal fin much extended, 
i.ijs. Dorsal scutes about twice as broad as long, finch ce ” , 
on flip i i : VGU 
v — - ttuuui/ nvice <is uruau . 
lated on the posterior border, and nearly 40 in number ; 
ridgo-scaleS about 25 in number, not serrated, decreasing 
backwards. , 
The so-called Diplomystus theta (Cope, foe. ext. 1877, P- 
loc. cit. 1884, p. 77 ; Clupea theta, Cope, BuU. U.S. « eoL 
errit. no. 2, 1874, p. 51), founded on an imperfect specimen- 
a so belong to this species. Diphrm/stus pcctorosus (Cope, 6 
1877, p. 810, and loc. cit. 1884, p. 76', pi. x. fig. 3) is also scar 
distinct. 
J'orm. <)• Loc. Eocene (Green ltiver Shales) : Wyoming. 
P. 5230. Fine specimen 0-46 in length, displaying the median fi 
and remains of the paired tins; found 10 nl \ u ^ug. 
Sillein, on the Oregon short line of railway, 5 lVC h a 
The jaws arc crushed slightly forwards, the hyoi a ^ , 
little downwards; the axial skeleton of the trunk 19 ^ 
well shown. Presented hij Samuel Lairxy, Cs'l" 1 
P- 7489-90. Two similar specimens, showing patches of ia | 
stout conical teeth on some of the inner bones 0 ^95. 
mouth. Purchased, 
P- 5218. Smaller fish 0-27 in length, lS g6. 
Presented by Lord Avebui Ji 
P- I860. Imperfect specimen 0-18 in length ; labelled “ Bear 
Idaho, but probably from the Green River * 1 p 
Wyoming. Eyerton Col 
P. 4928. Still smaller specimen displaying the ridge-scab s- gg. 
Presented by If. Lydelclcer, Es([ , 
49166. Small fish about 0-105 in length. Purchased, I s7 " 
Diplomystus brevissimus (Blainville). 
1818, Clu P ea brevissimus, II. D. de Blainville, Nouv. Diet. d’His - 1 
o vo1 - *xvii. p. 3C4. .. il7, 
1839-44. Clupea bremssima. L. Agassiz, Poiss. Foss. vol. v. P Ul ' p- 
Pi- bd. figs. C-9. „ 41, 
1850. Clupea hrenssima, F. J. Pictet, Poiss. Foss. Mt. Lihan, P- 
pi. viii. figs. 1 2. 
