228 



COLEOPTERA 



clavicorn (based and apiccd joints thicker tlutn middle joints) ; tarsi 

 three-jointed ; elytra sometimes covering abdomen, in other cases 

 leaving a variable number of segments exjjosed ; wings fringed. 

 This family comprises the smallest Insects ; Nanosella fungi being 

 only yl^j- of an inch long, while the largest Trichopterygicl is 

 only jl^ of ^■i^ inch. The small size is not accompanied by any 

 degeneration of structure, the minute, almost invisible forms, having 

 as much anatomical complexity as the largest Insects. A'^ery little 

 is known as to the natural history. Probably these Insects exist in 

 all parts of the world, for we \\&\& about eighty species in England, 

 and Trichopterygidae are apparently numerous in the tropics.-' 



Fam. 22. Hydroscaphidae. — Extremely minute aquatic Insects, 

 with elongate abdomen. Antennae eight -jointed. The other 

 characters are much the same aa those we .have mentioned for 

 Trichopterygidae. The family is not likely to come before the 

 student, as only three or four species from Southern Europe and 

 Xorth America are known." 



Fam. 23. Corylophidae. — Ifimcte beetles. Tarsi four-jointed, 

 but apiMCcring only three-jointed, owing to the hind joint being 

 concecded by the emarginate {or notched) second joint. Six free 

 ventrcd segments. Ifaxillae with only one lobe. Antennae of 



peculictr form. There are about 

 200 species of these little Insects, 

 but the family is apparently repre- 

 sented all over the world, and will 

 probably prove to be much more 

 extensive. The peculiar larva of 

 Orthojjerus brunnipes was found 

 abundantly by Ferris in thatch in 

 France. Mr. Matthews proposes 

 to separate the genus Ajjhanoceph- 

 alus as a distinct family, Pseudocory- 

 lophidae.^ In Corylophidae the 

 wings are fringed with long hairs, 

 as is the case in so many small 

 Insects : the species of Aphcmocepha.lus are rather larger Insects, 

 and the wings are not fringed ; tlie tarsi are only three-jointed. 



Fig. 107. — A, Larva of Orthoperus 

 brunnipes (after Perris) ; B, 0. ato- 

 inarius, perfect Insect. Britain. 



' Monograph, Trichoi^Urygia illustrata, by A. Matthews, London, 1872. 

 "^ For further information refer to Matthews, An Essay on Hydrosoapha, London, 

 1876, 20 pp. 1 pi. 3 Ann. Kat. Hist. (5) xix. 1887, p. 115. 



