130 Kev. A. E. Eaton on 
succinica, Hag. 1854 = A. succinica. 
Ithijtrichia, nov. gen.: type I. lamellaris. 
lamcllaris, nov. sp. 
Orthotrlchia, nov. gen. : type 0. angustella. 
angnstclla! M'Lach.: in //yr/rc^^^i^a, M'Lach. 
atra! Hag.: in Iltjdroptila, Hag. 
Oj:yetliira,Txas.'g<i,'a..: type 0. costalls. 
alhiceps, M'Lach. : in Hydroptila, M'Lach. 
costalis, Curt.: in Ui/fb-ojjtila, Curt. 
Fhrixocoma, nov. gen. : type P. sparsa. 
alhicornis, Hag. : in Ilijdrvptila, Hag. 
fcmoraUs, nov. sp. 
forcipata, nov. sp. 
'i fuscicornis ! Schn. : in ITijdrojjtila, Schn. 
occulta, nov. sp. 
2»ilcJu'ico7-uis, Pict. : in ITi/droptila, Pict., ! Hag. 
sparsa, Curt. : in Ilijdroptila, Curt. 
Family HYDROPTILID^E. 
Antennae shorter than tlie wings, much shorter in the 
female than in the male ; their basal joints not mnch 
stouter than the others. Ocelli present or absent. ]\Lixil- 
lary palpi ahke in both sexes, slender, sparsely hairy, five- 
jointed, but often apparently four-jointed owing to the 
obsolescence of the first joint. Labial palpi with the ter- 
minal joint enlarged. Tubercles of head and thorax with 
long coarse stiff hairs. Wings narrow, with very long 
fringes; the anterior Avith numerous erect or ascending 
hairs on the disk, and sometimes with an ap])cndage near 
the base of the post-costa ; the posterior Avith adpressed 
hairs on the disk, and without a fold. Legs slender, not 
very long ; the ])osterior tibia) more or less setose, some- 
times pinnatel}" hairy ; the anterior tibiiB spui'less, or with 
one spur ; the intermediate Avith tAvo or three, and the ])0S- 
tcrior Avith foiu- spurs. Abdomen short: in the male there 
is usually a horny process from the Axntral antepenulti- 
mate segment, the penis is long, and during life retracted ; 
in the female the antepenultimate segment beneath has 
sometimes an indistinct ])rominence, the ovipositor during 
life is retracted and is furnished Avitli tAvo tentacles at the 
apex. I have not detected any sexual differences in the 
palpi, the neuration of the Avings, or the tibial s])urs. 
The species Avith Avhich I am acquainted appear to shun 
excessi\e heat. Prominent olyects by the Avaterside, such 
