A Contribution to the Lower Devonian Faunas of Maryland 47 



tapering posteriorly; pleurae depressed on interior portions, abruptly- 

 deflected distally; each annulation bearing a longitudinal furrow which 

 runs from near the anterior side in the axial region obliquely to the middle 

 of the annulation, becoming obsolete distally ; the smaller anterior portion 

 of each annulation with a small spine at fulcral line as in C. crespedota. 

 Pygidium not seen. Surface of cephalon smooth; that of the thorax 

 covered by small irregnilar pustules, which are more numerous on the axis. 



This species bears a close resemblance to C. crespedota of the Hamilton 

 of New York, but is quite distinct. C. ccelehs of the Lower Helderberg 

 of that state differs widely from this species especially in the features of 

 the axis of the thorax. Only a single individual of this genus has so far 

 been reported from the Lower Devonian of Maryland. The exact horizon 

 is unknown. 



Occurrence. — Helderberg Formation. Cumberland. 



Collection. — George M. Boeder. 



Order PROPARIA 

 Family CALYMENIDAE 



Genus HOMALONOTUS Koenig 



HOMALONOTUS SWARTZI n. sp. 



Plate LXXXIX, Figs. 10-13; Plate XC, Figs. 1, 2 



Description. — Cephalon unknown. Thorax very broad, trilobation obso- 

 lete, axial portion broadly arched, pleural portions steeply descending; 

 segments curving gently forward in axial portion; posterior portion of 

 each segment broad axially, tapering gradually toward fulcra ; transverse 

 suture of each segment of nearly constant width, a narrower and less steep 

 secondary suture anterior to and parallel with the primary ; pleurae bend- 

 ing suddenly downward at fulcra, the transverse suture curving forward 

 distally, leaving the posterior portion of the segment very broad. 

 Pygidium large, subtriangular in outline, lateral margins at base nearly 

 rectilinear, posterior extremity not seen ; faintly trilobate, the faint longi- 

 tudinal furrows making with each other an angle of about 40° ; axis very 



