Genera and Species of Exotic Trichoptera. 251 
Fam. SERICOSTOMID. 
Genus Pycnocentria, nov. gen. 
Antenne graciles, alis longitudine fere zequales; articulo basali 
robusto, hirsuto, quam capite longiori. Caput transverse-sub- 
quadratum, utrinque tuberculo elongato instructum.  Palpi 
maxillares (¢) bisarticulati; articulo basali brevi, 2° elongato, 
robusto, sursum incurvato, pilis longioribus dense vestito ; 
(¢) 5-articulati; articulo basali brevi; 2° elongato, robusto ; 
3° secundo zquali, crassiori; 4° et 5° equalibus, brevioribus. 
Alze anticae apicem versus dilatate ; (¢) plica longitudinali 
apicem fere attingente et cellulam discoidalem obliterante ; 
alze postice anticis breviores, Jatitudine zquales, apice ob- 
tusee, (6) plica fere ut in anterioribus. Pedes hirsutius- 
euli. Calcaria 2-2-4; paribus duobus tibiarum posticarum 
juxtim positis, (¢ et 2.) 
Antenne slender, about the length of the wings; basal joint 
thick and strong, nearly straight, longer than the head. Head 
transversely subquadrate ; an oblique, elongated, oval tubercle on 
each side, placed close to the eye, and fringed with long hairs. 
Maxillary palpi of the male two-jointed; the basal joint very 
small and concealed ; the second joint long and thick, curved up 
in front of the face between the basal joints of the antenne, and 
furnished with long and strong hairs: of the female five-jointed ; 
the basal joint short; the second long and stout; the third equal 
in length to the second, but much thinner; the fourth and fifth 
shorter and still thinner, nearly equal. Labial palpi small. Me- 
sothorax smooth and polished, elevated in the middle. Anterior 
wings clothed with short and dense pubescence, dilated before 
the elliptical apex; in the male there is a Jongitudinal fold fur- 
nished with coarse hairs, extending nearly the whole length of the 
wing, and obliterating the discoidal cell, which is probably closed ; 
the apical veins radiating. In the female this fold is absent, and 
there is a long and narrow, closed discoidal cell. Posterior wings 
shorter than the anterior, and scarcely so broad as the broadest 
portion of the latter; obtuse at the apex; in the male with a 
longitudinal fold extending obliquely from near the base to near 
the apex of the costal margin, obliterating the subcosta and radius; 
the discoidal cell closed; apical forks four. Legs moderately long 
and slightly hairy; spurs 2-2-4; anterior and intermediate tibiz 
furnished each with a pair of moderately long and unequal apical 
