398 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 53 



DESCRIPTION OF PLATE 32 



PAGE 



Pccdeumias traiisifans, new genus and new species (See pis. 24, 25, 33, 34, 



41, and 44) 305 



Fig. I. A cephalon i mm. in length, exclusive of the intergenal spines. 

 X 16. U. S. National Museum, Catalogue No. 56810a. 



2. A dorsal shield with five thoracic segments and pygidium, 1.5 



mm. in length, exclusive of the long intergenal spines. X 12. 

 U. S. National Museum, Catalogue No. s68io&. 



3. A dorsal shield with seven or eight thoracic segments and 



pygidium, 1.75 mm. in length, exclusive of the intergenal spines. 

 X 10. U. S. National Museum, Catalogue No. 56810c. 



4. A dorsal shield 3.5 mm. in length with ten segments, pygidium, 



and large third thoracic segment. X 6. U. S. National 

 Museum, Catalogue No. 56810^. 



5. A dorsal shield of about the same size as that represented by 



fig. 4, that has a very narrow thorax. X 6. U. S. National 

 Museum, Catalogue No. 568i0(?. 



6. A dorsal shield 4.25 mm. in length, exclusive of spines, with 12 



thoracic segments and large third segment with pleura very 

 much prolonged. P3'gidium broken away. X 4- U- S. Na- 

 tional Museum, Catalogue No. 56810/. 



7. A dorsal shield 4.25 mm. in length, but shortened by compres- 



sion, with 13 thoracic segments and a small pygidium. X 4- 

 U. S. National Museum, Catalogue No. 568iog. 



8. Two small and very distinct cephalons. X 4- U- S. National 



Museum, Catalogue No. 56810/L 

 g. This figure is to illustrate the natural curvature of the spine on 

 the fifteenth thoracic segment. Natural size. U. S. National 

 Museum, Catalogue No. 56810J. 



10. An entire specimen of the dorsal shield from York, Pennsyl- 



vania, showing four very narrow segments and a plate-like 

 pygidium beneath the large spine on the fifteenth segment. 

 Natural size. U. S. National Museum. Catalogue No. 56810;'. 



11. Displaced pygidium and two posterior rudimentary segments of 



a dorsal shield in which the spine bearing segment is broken 

 away. X 3- U. S. National Museum, Catalogue No. 56810^. 



12. A cephalon compressed laterally so as to crowd the outer, rim 



in about the eyes and anterior portion of the glabella. Natural 

 size. U. S. National Museum, Catalogue No. 56810/. 

 13. A cephalon compressed longitudinally and broadened. Natural 

 size. U. S. National Museum, Catalogue No. 56810;;?. 



All of the specimens represented on this plate are from 

 locality (Sq), northwest of the City of York, Pennsylvania. 

 Most of them were collected by Prof. Atreus Wanner. 



