NO. 1442. JAMES TYPES OF BRYOZOA—BASSLER. 15 



ring abundantly throughout the various subdivisions of the Eden 

 shale. The species is characterized by slender, generally nonbifur- 

 cating segments (in consequence of which the complete zoarium must 

 have consisted of comparatively only a few rigid branches), and by 

 the numerous and small lateral branchlets springing out at nearly right 

 angles from the main stem. The segments are usually found sepa- 

 rated, specimens retaining more than a sequence of two or three being 

 extremely rare. In length they vary but little from the average of 

 7 mm. The basal segment is bifurcated and drawn outacuminately below. 



The types of P. grahami and P. dubia agree exactly in their zooe- 

 cial characters with those of P. deavelandl and differ from the last only 

 in each having a long striated pointed base and fewer or no lateral 

 branchlets. As here interpreted these three supposed species are 

 founded in two cases upon nothing further than basal segments and 

 in the third case upon the upper segments of one and the same species 

 of ArtJiTopoTa^ for which the name deavelandl is adopted and the other 

 two rejected. 



Occurrence. — Eden shale, Cincinnati, Ohio, and vicinity. 



ARTHROPORA KENTUCKYENSIS (James). 



Plate IV, lig. 5. 



Ptilodktya ke)ituck;/ensis James, Paleontologist, No. 5, 1881, p. 38. 

 Compare Arfhropom bifurcata Ulrich, Geol. and Nat. Hist. Surv. Minn., Final 

 Rep., Ill, Pt. 1, 1893, p. 178, pi. xiv, figs. 22-25. 



The types of Pt'dodictya kentuchyensls James consist of two frag- 

 mentary examples of a species of Arthropora., which maj^ prove to be 

 closely related to the Minnesota Black Ei ver form described by Ulrich " 

 as ArtJiropora Mfurcata. Better and more complete examples are 

 necessary before this relationship can be determined with certainty. 

 In the meantime both James's and Ulrich's names may be recognized 

 as valid. James's t3'pe specimens differ from other species of Arthro- 

 pora in having exceptionally narrow interzofBcial spaces. This charac- 

 ter, if constant, may very well be regarded as of specitic importance. 



The jointed, bifoliate zoarium will distinguish A. kentucJcyensis from 

 all associated bryozoa. With the exception of A. hifurcata, the other 

 species of Arthroporq are too different to require comparison. 



Occurrence.— ^TomYey shale of the Trenton, Ohio River bank oppo- 

 site Cincinnati, Ohio, in strata 10 or 15 feet above low watermark. 



ARTHROSTYLUS TENUIS (James). 



Helopora tenuis James, Paleontologist, No. 1, 1878, p. 3. , 



Arthro7iema tenuis Ulrich, Jour. Cincinnati Soc. Nat. Hist., V, 1882, p. 160, pi. 



VI, figs. 8-8c. 

 Arthrostylus, tenuis Ulrich, Geol. and Nat. Hist. Surv. Minnesota, Final Rept., Ill, 



Pt. 1, 1893, pf III, fig. We. 



«Geol. and Nat. Hist. Surv. Minn., Final Rep., Ill, Pt. 1, 1893, p. 178. 



