Sihvrian Fossils. 35 



the glabella usually are distinctly defined. The removable 

 part of the anterior border of the cephalon not being present, 

 its outline can not be determined. 



There is no indication that the posterior part of the pygi- 

 dium ever was acute. As far as may be determined from the 

 specimens at hand, it was blunt. Two forms of pygidia ap- 

 pear to be at hand. The smaller specimens, attaining a length 

 of 20 mm., have a narrower axial lobe anteriorly and both the 

 annulations and pleural segments are better defined. Of the 

 annulations, nine or ten are distinct, and of the pleural seg- 

 ments six or seven are distinct. The posterior border extends 

 only a short distance beyond the rather distinctly defined pos- 

 terior termination of the axial lobe. In the larger pygidia, 

 attaining a width of 53 mm., both the annulations and pleural 

 segments are less distinct, especially posteriorly. In one speci- 

 men there are seven distinct annulations, and the axial lobe 

 merges posteriorly into the surrounding parts of the pygidium. 



None of the specimens preserves any surface granules. 



West Union bed, at the blufif northwest of Martins, in 

 Lewis county, Kentucky. 



An excellent pygidium of Homolanotus, corresponding to 

 the larger specimens at IMartins, Kentucky, was found at 

 West Milton. Ohio, in the thin limestones which overlie the 

 typical Dayton limestone. The width of the axial lobe anter- 

 iorly is about To mm. There are ten distinct and one or two 

 indistinct annulations. There are six distinct pleural seg- 

 ments. The axial lobe merges posteriorly into a rather large, 

 smooth border. 



It is possible that more than one form is present among 

 the Xew York representatives of this species. 



Hoiiwlaiiofus occurs in the Waldron bed of Indiana. 



Dalmanites limulurus-brevicaudatus, var. nov. 

 Plate II. Figs. 20 A. B, C. 



Dalniaiiites Uiuulnnis is characterized by the slight angular 

 prolongation of the n:edian part of the anterior border of the 



35 



