442 NEW YORK STATE MUSEUM 



1894 G o m p Lj u s j) «^ r v ii 1 ii s Banks, Can. eut. 24 : 77 (recorded from Ithaca) 



1895 Gomplius parvulus Culvert, N. Y. ent. soc. Jour. 3:44 (recorded 



from Ithaca) 

 1897 G o m p h u s parvulus Needham, Can. eut. 29 : 165, 166, 167 (made the 

 type of a new genus, L a n t h u s : nymph, found at Ithaca N. Y. identified 

 with those described by Dr Hagen from Rocky creek Ky. in Trans. Am. 

 ent. soc. 1885, 12:281 and doubtfully referred by him toUropetala 

 (Tachopteryx) tboreyi: nymph figured, pi. 7, fig. 8-10) 



The habits of the images of this species are unknown. The few speci- 

 mens 1 was able to obtain at Ithaca in 1897 were all bred, and I saw no 

 imagos at large. The nymphs are very interesting httle fellows, quite as 

 different in certain habits as they are in structure and appearance from 

 other gomphines. They seem to prefer little, trickling streams fed by 

 springs, and burrow in beds of sand in the deeper parts. They are more 

 agile than other gomphine nymphs, burrow more rapidly, and, when with- 

 drawn from the water, unlike others, they feign death, and lie quite still 

 for a number of minutes. On account of this habit, as well as on 

 account of the mottled coloration of the body, they are much more diffi- 

 cult to detect while collecting than are the others which begin active 

 struggling as soon as the net is hfted above the water. 



Nymph. (PI. 18, fig. 6 and 20, fig. 8-10) Total length 23 mm; abdomen 

 14 mm; hind femur 5 mm; width of head 5 mm, of abdomen 6 mm. 



Body somewhat depressed, a little hairy on the genae and on the 

 tibiae, elsewhere bare ; head concave on the hind margin ; antennae, 

 with the two basal segments short and angular, the first a little larger, 

 the articulation between the first and second a little oblique, the third 

 segment obliquely oval, flat, one third longer than wide, with a depressed 

 smooth oval area within the scurfy pubescent marginal rim, the fourth 

 segment a minute round rudiment, at the inner apical angle of the third ; 

 labium mentum a little longer than broad, its front border appearing 

 convex by the rounded fringe of scales, in the midst and at the base of 

 which are four to six brown, minute quadrangular teeth ; lateral lobe 

 little arcuate, the distal angle produced and inclined internally, but hard- 

 ly differentiated from the six teeth on the inner margin, these teeth all 

 largest in the rriiddle, and a line connecting their summits would be con- 

 vex internally. 



Abdomen stocky, widened to the seventh segment, and thereafter nar- 

 rowed, most narrowed on the ninth segment; no dorsal hooks at all, 

 but a median impressed line ending on the seventh segment; lateral spines 

 well developed on segments 8 and 9, on 9 broadly triangular, and con- 

 siderably shorter than the loth segment, against the sides of which they 

 are closely appHed ; loth segment one half as long as the eighth, one 

 third as long as the ninth, three fifths as long as the superior and inferior 

 appendages; three fourths as long as the others. 



