714 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxvii. 



Subfamily ^VGPJ,I01S3"IISr^K. 

 ARGIA FUMIPENNIS (Burmeister). 



Sev^eral young specimens, collected at Gotha, Florida, on Januaiy 1, 

 1897, b}" Mr. Adolph Hempel. Numerous imagos of this species were 

 collected at the same place and time, and no other species of Argia. 

 These circumstances, as well as the structural characters of the nymphs 

 themselves, render the supposition very probable. 



Length (very immature) 10 mm., gills 4 mm. additional, abdomen 

 6.5 mm. 



Body thickset and rather short. Head depressed, with moderate 

 eyes, behind which the large hind angles are rather squarely truncated 

 behind and rounded and scurty hairy at the sides. The antenna? are 

 slighth' longer than the head. The labium (Plate XLIII, fig. 9) is 

 moderate, with the hinge extending posteriorly as far as the meso- 

 thorax. Mental setae wanting as in other members of the genus. 

 Lateral set* 2 and -a rudimentary third. Lateral lobe (Plate XLIII, 

 fig. 10) lacking the usual notch that separates the inner margin from 

 the end hook. 



Legs short. Wings reaching only the base of the second abdominal 

 segment. 



Abdomen rather short, cylindric, with the segments decreasing 

 slightly in length apically as far as the ninth, the tenth being slightly 

 longer than the ninth. Gills oboval, dark colored, the laterals, carinate 

 for a distance from the base, the carinas being low and spinulose and 

 extending outward three-fourths of their length. Color dark, with 

 a transverse blackish band near the apex. 



ARGIA sp.? 

 Plate XLII, fig. 4. 



This species differs from other known species of the genus in the 

 possession of stronglv triquetral gills, the lateral lamella? possessing a 

 high, sinuate lateral carina extending to the apex. The species appears 

 to belong to tepid or mineralized waters in the Rocky Mountains. 

 Full-grown specimens are from Bright Angel, Arizona, collected by 

 Messrs. Barber and Schwarz on July 13, and from White Sulphur 

 Springs, shore of Great Salt Lake, Utah, collected by Messrs. Hubbard 

 and Schwarz. There are 3"ounger specimens in the Illinois State Lab- 

 oratory collection, obtained by Professor Forbes in the Yellowstone 

 Park, and Professor Cockerell has taken immature specimens of it in 

 the tepid })rooklets that flow outward from the Las Vegas Hot Springs 

 in New Mexico.^' 



Length, 12 mm. ; gills. 1 mm. additional; abdomen, 7 mm.; width of 

 head, 1 mm,; of abdomen, 2.5 mm. 



« These are the nymphs referred to in Psyche, X, p. 136. 



