1903] XEEDHAM, COCKERELL :— NYMTHS OF ODOXATA 1 35 



unsuccessful. The hot springs themselves are apparently too hot for insect life 

 though they contain a variety of algae^ {Zygnenux cruciatum, Oscillaria froelichii 

 viridis, O. splendida, StigeocloniiDu tcniie, Ulothrix speciosa, Zygogonium parvulum, 

 Beggiatoa alba marina, Oedogonium sp., Spirogyra sp., Tetraspora sp., and Nostoc sp.). 

 The temperature of the water was found to be 121° Fahr. Search was next made 

 in the little streams running from the hot springs, and here nymphs were found, 

 but they proved to be referable to some unknown species of Argia. No further 

 investigations were made for several months, but in September Hypotiem-a nymphs 

 were at last found in abundance, clinging to stones in the Gallinas River at Las 

 Vegas Hot Springs. The place where they occurred is just where the hot water 

 runs into the river, and the river is perceptibly warmed in consequence. It does 

 not seem impossible that this condition has permitted the existence of the Hyponeiira 

 colony (derived in the first instance perhaps from the eggs of some wandering 

 individual) , the normal waters of the surrounding region being too cold for the 

 species. At the same place were found larvae of Anopheles pseudopimctipennis 

 Theobald, determined by Dr. L. O. Howard who informs us that the species was 

 lately described from Grenada, and is new to the United States, but adds that 

 there is a single specimen in the U. S. Nat. Mus., collected by Belfrage in Texas 

 and hitherto overlooked. Larvae have been sent to Dr. H. G. Dyar, who finds 

 them different from true A. punctipennis. There was also collected a leech, 

 Erpobdella pimctata Leidy (det. J. Percy Moore), apparently new to the fauna 

 of New Mexico. The Hyponeiira nymphs were not bred to the adult stage, but 

 as the generic characters can be seen in the nymphs, it is safe to assume that the 

 species is the same as that caught flying in the same immediate locality. If the 

 above suggestions concerning the origin and character of the Hyponeura colony 

 are correct, we may look for signs of modification tending towards the establishment 

 of a new race or species. At present it is not possible to compare sufficient num- 

 bers of specimens from different localities to determine whether such modification 

 exists, either in average or absolute characters. 



Hyponeura lugens Selys. 



A number of nymphs in alcohol, obtained from the Gallinas River, Las Vegas 

 Hot Springs, September, 1902. Apparently none of the specimens are fully grown, 

 but they are large enough to show the main features of the venation of the adult in 

 their developing wings, and thus to render certain their generic determination. 



Length 14 mm., gills 5 mm. additional ; abdomen 7.5 mm., hind femur 3.5 mm., width 

 of head 3.5 mm., of abdomen 2.5 mm. 



Body short, stout, smooth. Head depressed, widest across the rear of the large laterally 

 well-rounded and prominent eyes. Antennae 7-jointed. with the suture between the last two 



1 Collected by Mrs. Cockerell ; determined by Miss Smitli of the University of Nebraska. 



