SPH^RIIDAE. 109 



This family and the genus Ilydroscapha were established by 

 Dr. Le Conte upon a very minute aquatic insect collected by Mr. 

 Crotch in California. The characters given not liaving- been 

 verified by dissection were in part erroneous, and the antcniue 

 were described as 7-jointed. The Kev. A. Matthews has since 

 published an illustrated memoir on the genus, in which he shows 

 that the affinities are strongly towards Trichopterygidae, with 

 tendencies, also, as indicated by Dr. Le Conte towards Hydro- 

 philida3. 



Two species are known : H. natans from California, and //. 

 Crotchii from Spain. 



Fam. XYI.— SPHiERIIDAE. 



Body very small, rounded, convex, glabrous. 



Antennae 11-jointed, 1st and 2d tliickened ; last three 

 joints forming a loose club, thinly fringed with long hairs, 

 3d joint longer than the five following united. 



Maxilla with but one lobe, pointed and curved at the end, 

 and ciliate with small spines ; palpi -l-jointed, last joint nar- 

 ]'ow, subulate. 



Labrum prominent, as long as wide, slightly emarginate 

 in front. Mandibles short, broad, cleft at tip, with each part 

 of the division again cleft, inner margin with a broad coria- 

 ceous border. 



Prosternum very short ; meso- and mctasternum connate, 

 forming a large plate, separating the middle and hind coxae; 

 hind coxse laminate triangular, protecting the posterior legs, 

 and covering the 1st ventral segment. 



Middle and hind coxa? distant, the latter laminate, cover- 

 ing the thighs; logs short, front thighs toothed, front tibiie 

 broad; tibial spurs distinct; tarsi narrow, 3-jointed. 



Abdomen with but three ventral segments, the interme- 

 diate one short. 



Wings fringed with long hairs. 



The characters of this family have been fully set furlh by 

 Eri(;hs()n (Ins. Deutschl. iii. 38). 



The genus Spluerius alone represents Ihis family, with but 

 two species, one in Europe, the other S. jiolilus in California. 



