BRYOZOA. 425 



tubes bending rather abruptly from the axial to the per- 

 ipheral region, about 0.08 mm. in diameter in the spaces be- 

 tween the stars, while the two to six zocecia between the 

 rays of the macula* are slightly larger, sometimes having a 

 diameter of 0.13 mm.; apertures circular, with peristome. The 

 angular, thin-walled mesopores are arranged in star-shaped 

 macula*, and in the intermediate spaces surround the zooecia in 

 one or two series: they vary in size being generally smaller than 

 the zocecia, and largest at the center of a macula. Diaphragms 

 from one-half to one tube diameter apart in the peripheral 

 region of the zocecial tubes, and from one to two tube-diameters 

 apart in the axial region; very crowded and apparently upon 

 the same level in contiguous mesopores. 



This species resembles C. fischeri Ulr., but forms smaller and 

 thinner fronds, and has diaphragms throughout the zooecial 

 tubes; the disproportion in the size of the two sets of tubes is 

 much less, the zocecia are smaller, and a greater number of 

 mesopores is found surrounding the zocecia in this species. 



Position and locality: Cincinnati group, Wilmington, 111. 



LEIOCLEMA Ulrich, 1882. 



"Am. Pal. Bry." Jour. Cin. Soc. Nat. Hist. Vol. V. p. 141.) 

 (For generic diagnosis see page 376.) 



When this genus was proposed I was acquainted with the 

 type species, Callopora punctata Hall, only. Now, by extend- 

 ing the limits, fifteen species are united under the name. Five 

 are here described as new. the remainder, with one exception, 

 having been previously described by Prof. Hall as species of 

 Callopora. It is possible that more than one generic group is 

 included in the genus as now defined, but, as I found no char- 

 acters upon which to base satisfactory divisions, I have thought 

 it advisable to arrange them provisionally as one generic group. 

 The species are distributed as follows: L.? wilmingtonense Or., 

 in The Cincinnati group; L. singulare, asperuw, floridum, and (?) 

 laminatum of Hall in the Niagara group; L. cellulosum, para- 

 siticum. and ponderosum of Hall, in the Lower Helderberg 

 group: L. occidens (Fistulipora occidens Hall and \Vhitfield)m the 

 Hamilton group; L. wachsmuthi and subglobosum Or., in the 

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