488 

 2. Tanytarsus dives Johannsen 



Tanytarsus dives JohaDUseu, Bull. 86, N. Y. State Mus., 1905, p. 288. 



Larva. — Length, 6-y mm. Blood-red, with a greenish tinge on 

 the sides and a prominent hump on the anterior part of the dorsum 

 of the last segment. Head dark, about one and a half times as long 

 as wide; antennae much elongated, about two thirds as long as the 

 head, or fully as long when they are measured to the tips of the two 

 long filaments of the second antennal segment. The first joint long 

 and slender, with a slender seta on its side and a spur at the tip near 

 the base of the second segment ; second segment about three times 

 as long as wide, with two long filaments at the tip near base of third 

 segment. The third and fourth segments slender, delicate, and in- 

 conspicuous, the two taken together less than the length of the sec- 

 ond joint. The dorsal sclerite of the head not distinctly separated 

 from the laterals. Upon the dorsal aspect of the head are eight pairs 

 of rather long setae, two immediately behind base of antennae close 

 to median line, two on lateral margins, one behind and the other in 

 front of eye spots, and two on disc in transverse line with the one 

 behind eye spots. Labium similar to that shown in Figure 14, Plate 

 XXIX. The body has no prominent hairs and no ventral blood-gills. 

 (This description is partly copied from Johannsen, as my single ex- 

 ample is in poor condition.) 



Pupa. — "Length, 4 to 5 mm. Dusky, with the thoracic respira- 

 tory organs each consisting of a single slender shaft, with lateral 

 hairs, about as long as a single abdominal segment. The dorsal sur- 

 face of the abdomen is marked with minute setae as shown in figure, 

 [PI. XXXIX, Fig. 9]. This figure shows segments two to six in- 

 clusive. The dorsum of the second segment is nearly uniformly cov- 

 ered with fine, very short, microscopic spines, [and has] four or five 

 pairs of pale setae and the usual chitinous, longitudinally ridged, 

 posterior margin ; the third has anteriorly two patches of short black 

 spines, two patches of fine hairs, the rest of its dorsal surface punc- 

 tate with minute spines, and five or six pairs of pale setae ; the 

 fourth, fifth, and sixth segments each have two dense patches of 

 short black spines near the anterior margin, [are] sparsely punctate 

 with minute spines and provided respectively with about eight, 

 seven, and five pairs of pale setae. The eighth segment has the usual 

 lateral fins, with its filaments, and has also the combs, each with five 

 or six prominent black teeth." — JoJiaunscn. 



Imago; Male. — Black or brownish black, shining. Spaces be- 

 tween the vittie sometimes vellowish brown. Legs fuscous, tibiae 



