154 Ciucinuati Society of Natural History. 



one-luindredths of an incli or more. Length several times 

 the breadth, so that the spaces are frequently long and narrow. 



" Locality. — Covington, Ky., 150 feet above low water in the 

 Ohio River; run emptying into the Little Miami River, near 

 Symmes Station, on the Cincinnati, Washington and Balti- 

 more R. R. 



"Remarks. — Mr. Ulrich informs me that a study of better 

 material than that upon which his original description was 

 based has convinced him of the identity of three species 

 enumerated in his ' Catalogue of Fossils occurring in the Cin- 

 cinnati Group,' 1880, p. 6. These are D. irregulare, Hall (U. 

 P. James), Dictyograptus rcticiilatus, Ulrich, (named, but not 

 described) and Inocaulis arbuscula, Ulrich. 



" In the cabinet of the late Mr. U. P. James are two speci- 

 mens identified by him as D. irregn/arc, Hall. A comparison 

 of these with Mr. Ulrich's figure of hwcanlis arbuscula .seems 

 to rather favor his views of the identity of the two forms. I 

 may also add that the species is undoubtedly a Diciyouema, 

 and it is distinct from the Calciferous form. Specimens of the 

 latter from the type locality show the branches more angularl}- 

 bent, so the meshes are more nearly rectangular ; whereas 

 in the present form the branches are more slender and more 

 roundly curving, thus making the interspaces rounded dia- 

 mond shape." 



In the original description Mr. Ulrich compares his species 

 to Inocaulis bclliis, H. & W., from the Niagara. J. W. Spencer 

 says (Bull. Mus. Univ., Missouri, No. i, 1884, p. 13) that it 

 " resembles and is probably a species of Calyptograptns,'' a 

 new genus proposed by himself (Can. Nat., new ser., vol. 

 8, 1878). 



The original description of D. irrrgiilarr, Hall, is as fol- 

 lows: "Frond spreading, diffuse, branches lax, frequently 

 bifurcating; bifurcations unequal ; branches equal to one-half 

 the usual width of the interspaces, or a little less ; connecting 

 filaments generally slender, expanding with their junction 

 with the branches. Fenestrules extremely irregular in form 

 and proportions, varying from a width greater than the 

 length, to a length three or four times as great as the width ; 

 those with a length and l^readth nearly equal, often appear 

 hexagonal. Near the base of the frond the fenestrules are 

 sometimes elongate and triangular. Cellules undetermined. 



