March, 1914-] WoODRUFF : OpHIOGOMPHUS JOHANNUS. 61 



turn out to be only a subspecies of chilensis seems to be indicated 

 by a series of specimens in my collection taken by the Yale Expedition 

 at Urubamba, Peru (9,500 ft.)- These are intermediate between typi- 

 cal specimens of chilensis from Valparaiso in the breadth of the pro- 

 notum, and are much more pilose, with the pubescence on the gaster 

 of a brilliant orange brown color. 



THE NYMPH OF OPHIOGOMPHUS JOHANNUS 

 NEEDHAM. 



By Lewis B. Woodruff, 



New York. 



Of the seven recognized species of Ophiogomphus occurring in 

 northeastern North America, the nymphs of the three following 

 species are still undescribed : O. anomalns, Harvey, O. maincnsis, 

 Packard, and 0. johannus Needham. As it has been my good fortune 

 to observe the latter in the process of transformation on more than 

 one occasion, the description of its nymph is now available. This 

 species is by no means rare locally along the stony brooks in the hills 

 of northwestern Connecticut, on the occasional sandy bottoms of 

 which they apparently pass their larval existence. Toward the end 

 of ^May they crawl out at such points, that is where the margin is 

 sandy, there to await the splitting of the thoracic dorsum. This oc- 

 curs on the ground at not more than three or four feet from the 

 brook's edge, and often, if not invariably, several hours after sunrise. 



The following description of the male nymph of this species is 

 made from very perfect exuviae taken at Litchfield, Conn., May 31, 

 1909. and preserved with the emerged imagos : 



Total length 26 mm.; of abdomen 16 mm.; of hind femur 4.5 mm. Width 

 of head 5 mm. ; of abdomen at 5th segment 6.5 mm. 



Legs, gense, sides of antennse and lateral margins of abdomen sparsely 

 hairy. 



Color olivaceous, mottled with yellowish and fuscous ; wing cases varie- 

 gated with pale and dark markings ; femora and tibise with broad pale bands 

 just before the apices ; a quadrate yellowish spot on each lateral dorsum of 

 abdominal segments two to nine inclusive, in each of which are four round 



