CRUSTACEA. 15 



shales, the lobes of the pygidial fimbria, instead of being Bat, broad and 

 contiguous, are more lanceolate, relatively narrow, elevated along the middle, 

 with the apex nearly terminal. Upon careful comparison of these pygidia 

 with Dr. Green's description of Cryphaus Calliteles, it appears beyond question 

 that the species was founded upon a pygidium of this character. The original 

 specimens of both C. Calliteles ami ('. Boothii were derived from the same 

 locality, viz.: Huntingdon, Huntingdon county, Pennsylvania. The varietal 

 feature of the pygidium with its associated characters is evidently a genetic 

 difference, as it is apparent in the youngest individuals observed, and it 

 therefore seems advisable to recognize in Green's species, C. Calliteles, at 

 least a variety, with the following differential characters: 



Dalmanites (Cryph.-eus) Bootiu, var. Calliteles.* 



PLATE XVI, PIGS. 5-22; AND PLATE XVI a, FIGS, hit. 



Cryphu us Collitelus, Greek. A.mer. Journ. Science, vol. \xxii. p. 346. 1^;;7. 

 Dalmanites Boothii, Hall. Illustrations of Devonian Fossils, pi. xvi, figs. 7,8, 12, 1 1. [S76. 

 (?) Cryphu us calliteles, '. Kayser. Abhandl. /. Geolog. Specialkarte von Pi-, and d. Thlir. St.. vol. ii. part 



4. p. 32, pi. iii. fig-. 10. 187S. 



Genal spines long, Hat, tapering to an acute extremity and reaching to the eighth 

 thoracic segment; slightly depressed laterally and distinctly grooved by the 

 occipital furrow for two-thirds their length. The occipital ring is unusually 

 wide, and hears a stout spiniform node at its center. The first thoracic 

 segment has a node or faint spine upon the axial line, and thence backward 

 to the pygidium the spiniform nodes increase in size; the first annulation of 

 the pygidium also bears a short spine. The lateral lobes of the pygidial 

 fimbria are distant, narrow, lanceolate, elevated along the middle, having the 

 apex terminal. The axial lobe is shorter than the rest, hut more elongate 

 than in D. Boothi and acutely angled. The surface of the test is mostly very 

 faintly granulose, the glabella and pygidial lobes generally quite smooth, the 

 posterior portion of the genal spines more strongly granulose than any other 

 part of the surface, and the thoracic segments furnished with single rows of 

 low pustules. Abundant material representing this species affords evidence 



*The specific name of this species :is originally published is Collitelus, probably a typographical error 

 for the personal noun Calliteles. 



