414 



The Ohio Naturalist. 



[Vol. Ill, No. 6, 



serrate, extending posteriorly two-thirds of length of median lobe, 

 and separated from it by almost its own width. Outer lobule 

 rudimentary, rounded. Third lobe rudimentary ; lobules faintly 

 serrate. The oland-spincs are arranged as follows: i, i, i, i, 

 3-4 ; large and conspicuous, decreasing in size toward the median 

 lobes. Spines on dorsal surface are arranged as follows : ist on 

 base of median lobe, laterad of center ; 2nd at base of second lobe, 

 between the lobules ; 3rd at base of third lobe ; 4th about two- 

 thirds of distance to penultimate segment, posterior from the 

 fourth gland-spine. On the ventral surface the spines are shorter 

 and located just laterad of the corresponding dorsal spine. First 

 and second rows of doisa/ oland-orifices are absent ; third row rep- 

 resented by 3-5 in the anterior and 3-6 in the posterior group ; 

 fourth row with 2-4 in anterior and 5-7 in posterior group. 

 Median group of circiimocnital gland-orifnrs^ 4-10 ; anterior later- 

 als, 15-21 ; posterior laterals, 8-14. 



Habitat : Abundant on Gleditsia h'iaca)it/ios (Hone)' lyocust), 

 at Columbus, Ohio. 



[The author wishes to thank Prof. Cooley for his expert opinion on this species, and 

 also for his many favors.] 





a. 



EXPLANATION OF PIRATE. 



Fig. I. — Scale of female. Fig. 2. — Scale of male. 



Fig. 3. — Pygidiimi of female. Fig. 4. — Part of Fig. 3, enlarged. 



