NEUROPTERA— TRICHOPTERA— HYDROPSYCHID J3. 1 79 



which alone are found, and that therefore the larvae of Hydropsychidae 

 must have frequented perforce the neighboring streams, where such larger 

 stone surfaces could have been found. If cases should be found they will 

 be likely to be those of the larger Phryganidge (next most abundant after 

 the Hydropsychidse), composed of vegetable fragments. Three species and 

 seven specimens only of this group have been found. (February, 1884.) 



Subfamily HYDROPSYCHIDSE Curtis- 



Although no members of this group have been found in the stratified 

 deposits of the Old World, about half of the numerous species described 

 from the Baltic amber belong to it, including several genera. It is interest- 

 ing, therefore, to find that about three-fourths of the Florissant caddis-flies 

 described in this work belong here, and in the material too poorly preserved 

 to bring before the public the greater part also belong here. Here, too, the 

 species seem to be far the most abundant in individuals. Among those de- 

 scribed below are not a few very aberrant forms, which I have been at a loss 

 to determine, as certain of them seem on some accounts to be more nearly 

 related to the Leptoceridge. At the present day the subfamily appears also 

 to be the most numerous in species in the northern hemisphere, and they 

 are found all over the world. The larvae more commonly frequent running 

 than standing water, make fixed cases, and are believed to be to a large 

 extent carnivorous. 



Taile of the genera of Hydropsi/chidw. 



(Only the extinct, newly described genera, in which the fifth apical cell and sometimes some of the 

 other apical cells of the fore wings are wanting, are here tabulated.) 

 First apical cell present. 



Second apical cell present. 



Median cellule one-tbird or scarcely more than one-third as long as the wing ..3. Derobrochus. 

 Median cellule one-half as long as the wing 4. Litobrochus. 



Second apical cell absent ,5. Leptobrochus. 



First apical cell absent. 



Discoidal cell open 6. Mesobrochiit. 



Discoidal cell closed 7. Paladkella. 



1. HYDROPSYCHE Pictet. 



The two species placed here by us from the American Tertiaries are 

 referred to the genus in its ancient wide sense as representative of the group 

 to which it belongs. No fossils have previously been referred to it. 



