New Species of Devonian Fossils. 149 



length of al)out 100 mm. and a width of 105 mm. A smaller 

 entire individual has a length over all of ahout 120 mm. 



Discussioji: This giant trilobite may be readily distinguished 

 from the associated specimens of D. pleuroptyx by the facts that 

 the second, third, and fourth glabellar lobes are confluent at 

 their extremities, and that the facial sutures lie in distinct 

 grooves. 



The fusion of the glabellar lobes indicates that this species 

 belongs to the group of D. anchiops, D. stemmatus, and D. 

 dolhcli, whose characters have been discussed by Clarke. The 

 new species is remarkable not only for its great size, but also 

 for the degree of fusion of the glabellar lobes at this early 

 horizon. 



Occurrence: Ross limestone, at Olive Hill, Pyburns Blufif. and 

 other localities in Hardin County. 



Dalmanites retusus, n. sp. 

 Plate V, fig. 3 



Description: Species known only from the pygidium, which is 

 semi-elliptical in outline, broader than long, and evenly rounded 

 behind without any spinous extension. Axis low, only slightly 

 arched, rapidly tapering, marked by fourteen or fifteen annula- 

 tions, the last of which are very indistinct as the axis becomes 

 obsolete posteriorly. Pleura gently arched, marked by ten or 

 eleven broad ribs separated by narrower grooves, all of which 

 become obsolete before reaching the edge, leaving a smooth 

 margin about 4 mm. wide. 



Dimensions: Length, 27 mm. ; width, 41 mm. ; convexity. 5 

 mm. 



Discussion: The absence of a spinous extension of this 

 rounded pygidium is sufficient to distinguish it from all other 

 species of Dalmanites except D. aspinosiis of the Decker Ferry of 

 New Jersey. Compared with this much earlier form, the pygi- 

 dium of the new species is proportionately wider and more 

 broadly rounded behind, its axis tapers more rapidly, and it pos- 

 sesses a smooth marginal border. 



Occurrence: Occurs sparingly in the Birdsong shale at Perry- 

 ville, Big Lick Creek, Birdsong Creek, the old Swayne's mill 

 locality, etc. 



