NORTH AMERICAN EARLY TERTIARY BRYOZOA. 207 



Measurements. Opesiumof thon=QAS mm.,, , ,, . \Lon=OA 



. < , Onychocellarium 7 



Onvchocellana ?<m=0.10mm. J (lon=0.2t 



proximal border. The onychocellarium is as large as the zooecia, falciform, acumi- 

 nate, with an elliptical opesium. 



[Z o?i= 0.40 mm. 



i=0.20 mm. 



Opesia of fAo = 0.20-0.24 mm. 7 \ 7-3=0.30-0.32 mm. 



zooecia Uo=Q.l<M).14 mm. a 1 1& =0.20-0.24 mm. 



.Affinities and variations. This species is much smaller than Onychocella angu- 

 losa Reuss, 1867. Its polypidian convexity is scarcely apparent and disappears 

 totally in the marginal zooecia where the opesium is then elliptical. 



Occurrence. Lower Jacksonian: Three and one-half miles southeast of Shell 

 Bluff post office, Georgia (rare). 



Cotypes.Ca.t. No. 63862. U.S.N.M. 



ONYCHOCELLA CELSA, new species. 



Plate 32, fig. 25. 



Description. The zoarium incrusts Cellepores. The zooecia are distinct, elon- 

 gated, ogival, sepai'ated by a furrow or by a salient thread. The cryptocyst is 

 deep, smooth, a little longer than the opesium ; the opesium is placed high, ogival ; 

 the opesiular indentations are rather deep and nearly symmetrical. The onycho- 

 cellarium is as large as a zooecium, lozenge-shaped, somewhat falciform; the 

 opesium is large, elongated, median, oval, the point below. 



Measurements. Opesia |7(,o=0.15 mm. [.2=0.40-0.45 mm. 



of zooecia \7o=0.12 mm. la i 7-=0.35-0.40 mm. 



Opesia fkon=0.2F> mm. , . [Zo?i=0.45-0.50 mm. 

 of onychocellaria \lon=O.W mm. a | fo.=0.20-0.30 mm. 



Affinities. This species differs from OnychoceUa georgiana in its salient 

 polypidian convexity. It, differs from OnychoceUa, angulosa, Reuss, 1845, in its 

 smaller micrometric dimensions, its less falciform onychocellaria, and its more 

 symmetrical and regular opesium. From OnychoceUa laciniosa it may be dis- 

 tinguished by its elongated and nontrans verse opesium. 



The only specimen found has been figured. It is a very beautiful example 

 of this genus. 



Occurrence. Lower Jacksonian (Moodys marl) : Jackson, Mississippi (rare). 



Holotypc.C&t. No. 63958, U.S.N.M. 



ONYCHOCELLA LACINIOSA, new species. 



Plates 32. figs. 20, 27. 



Description. The zoarium incrusts shells. The zooecia are hexagonal, con- 

 fluent with one another by their mural rim. The cryptocyst is flat, smooth, 

 depressed, longer than the opesium; the opesium is semilunar. transverse: the 

 polypidian convexity is slightly projecting; the opesiular indentations are small 

 nnd unsymmetrical. The onychocellarium is falciform, narrow, as long as the 



