252 



NEW YORK STATE MUSEUM 



(2.5 mm) and conspicuous, furnished with short, stout nema, that some- 

 times widens and terminates club-shaped. Primary thecae originating 

 near the aperture and diverging below at the level of or below the latter. 

 Thecae numbering 10 in 10 mm in proximal part and 8 to 9 in the same 

 space more distally ; three to four times as long as wide ; overlapping two 

 fifths their length in the proximal and one half in the distal portions, 

 inclined at angles increasing from 18 to 30 in distal direction. Apertural 

 margin straight, slightly inclined to axis, producing an acute denticle. 



Fig. 156-59 Did vmograptus serratulus (Hall). Fig. 156 Proximal portion of the variety j u v e n- 

 alis. Fig. T57, 158 Proximal portions of lypical specimens. Fig. 158 That ot the counterpart of the type 

 specimen (in New York State Museum). Fig. 159 Distal portion of same specimen. All x 5 



Position and localities. The type of this species is from the Normans- 

 kill shale at Kenwood near Albany. The same slab bears the cotype of 

 I ) . subtenuis and specimens of N e m a g r. g r a c i 1 i s, X . g r a c i 1 i s 

 van surcularis, Climacogr. parvus and Lasiogr. mucro- 

 natus. The species occurs also at Stockport, Columbia ah, in association 

 with D i c r a n og r. r a m o s u s, 1 ) i tl y m o g r. sagitticaulis, C 1 i m a- 

 cogr. parvus and Retiogr. gei ni-tz ianus, and at the power house 

 north of Lansingburg. It is rare in these localities and has not been 



