188 Cincinnatt Society of Natural Fitstory. 
ventral margin gently convex, most prominent in the posterior 
half. Marginal frill wide, but frail and easily broken away, geni- 
culated in cross-section; within it a deep channel. Anterior lobe 
small, isolated, vertically elongate, papillose, situated near the 
anterior margin. ‘The latter with a row of small spines. Mesial 
and posterior lobes connected, together forming a slightly oblique 
loop; the former terminating at the dorsal edge in a large, papillose, 
and greatly elevated knob; posterior lobe well-defined, consisting 
of three divisions, rising step-like over each other, the highest 
part, an upward extension of the ventral prolongation of the mesial 
lobe, forming the posterior border of the deep sulcus. 
In some respects the departure from typical Ctenobolbina, men- 
tioned under the preceding species, is even more apparent in this. 
Such species as Lollia granifera (see pl. XII, figs. 2 a) must be 
related rather closely, and it may have been better to refer this 
species to Bolla also. 
Position and locality: Devonian Bryozoa bed, Falls of the Ohio. 
CTENOBOLBINA MINIMA, N. Sp. 
LAGI KV 
Size of right valve: Length, 0.4 mm.; height, o.26 mm. 
I propose the above name for a small Primitia-like species from 
the Hamilton shales, at 18 mile creek, near Buffalo, N. Y. I 
place it under this genus chiefly because of the strong, oblique 
sulcus, and the general resemblance which it presents to C. dispz- 
nosa (see pl. VII, fig. 6) which I am confident is congeneric with 
C. alata and C. ciliata. ‘The Hamilton form has a narrow flange, 
and has the ventral spine situated far behind, while the dorsal 
spine is wanting, unless a minute tubercle on the posterior side of 
the sulcus represents it. Surface smooth, moderately convex. 
BOLLIA UNGULA, Jones. 
Plate XIV. his. ©. a0: 
Bollia ungula, Jones, (Claypole MS.) American Geologist, Dec. 
1889, Pp. 338, figs. 10-12. 
Size: Length, 1.2 mm.; height, 0.77 mm. 
The specimens of this species from the Devonian Bryozoa bed at 
the Falls of the Ohio, agree very closely with Prof. Jones’ figures, 
