252 The Ohio Journal of Science [Vol. XVII, No. 7, 



lobes by almost equally deep but narrower furrows; viewed from the 

 rear, these lobes lie distinctly below the general surface of the median 

 and third lateral lobes. Third lateral lobes equalling in width the 

 posterior end of the median lobe, pyriform with the narrow end directed 

 toward the median axis of the glabella ; distal end about four millimeters 

 from the suture line at the palpebral lobe. Occipital lobes small, 

 triangularly ovate, with the narrower end directed toward the axis 

 of the glabella, the width equalling three-fourths of the length, sharply 

 defined from the third lateral lobes and from the occipital segment by 

 narrow furrows. In width, these occipital lobes equal almost one-half 

 of the width of the third lateral lobes, but they are low and much less 

 conspicuous. Occipital segment subtriangular when viewed from the 

 front, owing to the prolongation of the median parts into a spine. 

 The length of this spine can not be detennined from the specimen at 

 hand since only the basal portion remains. Immediately anterior to 

 the occipital segment and posterior to the median lobe the surface 

 of the glabella is strongly depressed. Anteriorly the median and com- 

 pound anterior lateral lobes are strongly defined from the border of the 

 cephalon by a deep furrow, fully a millimeter and a half in width anterior 

 to the median lobe. The facial suture is about 3 mm. distant from the 

 lateral margins of the compound anterior lateral lobes, as far as the 

 very small palpebral lobe, beyond which it ctu-ves almost rectangularly 

 outward, its further course not being shown by the specimen at hand. 

 General surface of the glabella thickly covered with tubercles of various 

 sizes. Some of the larger of these probably supported short spines. 

 Several of these may have been scattered along the middle third of the 

 median lobe and one or two may have been present near the middle 

 of the third lateral lobes. It is certain that the two conspicuous spines 

 near the anterior end of the median lobe, and the single conspicuous 

 spine at the distal end of the third lateral lobes, figured by Weller 

 (Trilobita of Niagaran limestone in Chicago area, Chicago Acad. 

 Sciences, 1907, pi. 22, figs. 1-4) from the species of Trochurus 

 occurring in the Chicago area are absent in the Ohio specimen here 

 described. 



From the Cedarville dolomite at the eastern Mills quarry, 

 southwest of Springfield, Ohio. 



The type of Trochurus phlyctainodes, (Plate XII, Figs. 1 A-D), 

 described by Green under Calymoic, was fovmd within two miles of 

 Springfield, Ohio, in limestone used to construct the National Pike. 

 To anyone acquainted with the Springfield area it is evident that the 

 only limestone within a convenient distance from the National Pike is 

 located west of Springfield, north of Mad River, within a mile of the 

 eastern Mills quarry at Limestone City, and that the so-called limestone 

 was the rock known at present as the Cedarville dolomite. Casts of 

 this type, numbered 54 in the series of casts prepared by Green, are 

 preserved in the U. S. National Museum at Washington, at the Amer- 

 ican Museum of Natural Historv in New York Citv, and elsewhere. In 



