468 SAMUEL II. SCUDOER ON THE 



2. Neorthroblattina lakesii. 



]^1. 42, figs, i), 15. 



NeorthroUatUna JaJcesii Scudd., Proc. Acad. ISTat. Sc. PhihuL, 1885, 109. 



The costal mai-giu is arched as in the last species, and the inner margin has an almost 

 equal opjjosite curvature. The externomedian vein has a very sinuous course, and forks 

 before the middle of the wing with abundant neuration, occupying on the margin the en- 

 tire tip of the wing, and almost the outer half of the lower margin, while the internome- 

 dian is reduced to an archmg veiu, extending but little beyond the anal fuiTow, and with 

 only two or three branches; the anal veins are all parallel to the anal furrow and simple. 



A single stone with its reverse shows the pi'othoracic shield, which is broadly and 

 transversely oval, a little moi-e tlian a fifth broader than long, tolerably regular, with 

 vei-y broad sides, the anterior margin scarcely bent in the middle, the curve of the hind 

 margin somewhat llattened; uniformly and rather sti'ongly domed, the lateral margins a 

 little flattened, and with a median, slight, but rather abi-upt and pretty lar'ge, rounded 

 depression . 



Length of fore wing, 9 mm.; breadth, 3.5 mm.; length of prothoracic shield, 3 mm.; 

 breadth, 3.65 mm. 



Two wings, one of them with its reverse, and one shield with its reverse, Avere found, 

 ISTos. 34:, 35 and 82, 76 and 77. Named after Prof. Arthur Lakes of the School of Mines 

 in Golden, Colorado, who first made known these beds, this species being one of the first 

 discovered by him. 



3. Neorthroblattina rotundata. 



PI. 42, figs. 7, 8. 



Neorthrohlattina rotundata Scudd., Proc. Acad. Nat. Sc. Philad., 1885, 109-110. 



The costal margin in this species is very strongly arched, while the inner margin is 

 straight, giving a very different aspect to the wing. It closely resembles the pi'cceding 

 species in the mediastino-scapular and anal areas, and also in the peculiarities of the 

 externomedian vein, excepting that the latter does not encroach to so large a degree 

 upon the internomedian, the terminal oflshoot of which creeps along the border so as to 

 limit the marginal extent of the externomedian area almost as much below as above, al- 

 though the branching of the externomedian vein is scarcely lessened thereby. 



Length of wing, 8.5 mm.; breadth, 3.3 mm. 



Three specimens, all with reverses, Nos. 78 and 79, 100 and 101, 102 and 103. 



4. Neorthroblattina attenuata. 



PI. 42, fig. 1. 

 Neorthroblattina attemiata Scudd., Proc. Acad. Nat. Sc. Philad., 1885, 110. 



This species departs from the typical forms in its slenderness and pointed apex, but 

 it agrees so fairly in general structnre that it would best be placed here. The costal mar- 

 gin is not regularly arched, being flattened mesially, while the whole wing tapei-s regu- 

 larly in the apical half; the inner margin is also arcuate, and the tip bluntly pointed. The 



