916 ZOOLOGY— INSECTS. 



states the absence of gills in living specimens of D. intricate/, and D. alpina. 

 Formerly, the genus Ptcronarcys was the only known exception for its gill 

 bearing images among the class of insects ; now, besides the above 

 described Dictyopteryx, there are two other gill bearing Perlid genera 

 mentioned by Di\ Gerstaecker — Damphipnoa titchenalis from Chili, a genns 

 closely related to Ptcronarcys ; and Nemura cinerca and N. nitida, with its 

 male, iV. lateralis, both from Europe. 



The papers by Dr. Gerstaecker are published in the Festschrift sum 

 hundertjdhriyen Bestehen der Gesellschaft naturforscliender Freunde, Berlin, 

 1873, 4to, p. 60, with figures; and Sikungsbcricht derselben Gesellschaft, 

 October 21, 1873, p. 99. 



Taken at Roaring Fork, Colo., by Dr. J. T. Rothrock. 



ISOPTERYX. 

 ISOPTERYX CYDIPPE, Hagen. 



Some specimens, much damaged, presumably of this species, were taken 

 in Southern New Mexico in September, 1874, by Dr. 0. Loew. 



Fam. ODONATA. 



OPHIOGOMPHUS. 

 OPHIOGOMPHUS SEVEETJS, Hagen. 

 Ophiogomphus severus, Hagen, U. S. Geol. Surv. Terr., 1S73, 591. 



Greenish-yellow; head and mouth parts greenish-yellow; labium and 

 labrum paler ; antennae black ; part between the eyes black, forming a 

 transverse black band above the base of the front, excised in the middle ; 

 vertex greenish-yellow, flat, the front margin deeply notched, the sides of 

 the vertex cariniform, curved in an exact semicircle around the lateral 

 ocelli ; occiput greenish-yellow, with a small, black band along the superior 

 border, beginning near the occiput. Thorax greenish-yellow, an ill defined 

 brownish spot on the dorsum each side near the wings ; the crest of the 

 sinus not exceeding the bifurcation, black, and an incomplete blackish band 

 on the humeral suture beginning at the wings. 



(Three males and two females from Colorado, in alcohol; a single male 

 from Yellowstone, preserved dry, shows the following pattern): — Dorsum 



