10 PROCEEDINGS OF THE NATIONAL. MUSEUM vol.79 



the veins, where the brown color is more distinct. Venation brown ; 

 at cross veins there are mostly brownish spots; a somewhat paler 

 spot is placed between DC and the end portion of CuP, occupying 

 the distal portion of MC. SC unites at its end with R and thus 

 a short common vein is formed, ending very near to Rs; first apical 

 fork rather long, discoidal cell short ; median cell long, fourth apical 

 fork beginning nearly at the same level with the third fork; cross 

 vein between basal portions of M.^ and M3 placed quite as in 

 Hydafopsyche melU. Male : Tenth segment formed as in H. f rater Ul- 

 mer, but longer ; its basal portion, seen from above, is broad, triangu- 

 lar ; distal portion elongated ; its apical portion is divided by a median 

 fissure into two portions, as in H. f rater ; before this apical portion 

 is placed, above, a minute tooth. Lateral appendages of the tenth 

 segment are long, directed upward, and very slender; they are rod- 

 shaped, without hairs. Inferior appendages resembling those in 

 Hydatopsyche melli Ulmer; basal joint very obliquely truncate at its 

 apex, which is somewhat dilated; second joint rather slender, in its 

 distal portion curved upward and inward. Penis thick and long, in 

 structure somewhat similar to that of Hydrcmianicus frater and 

 Hydatopsyche inelli; its end portion is divided by a deep excision 

 above into two side portions, which are broad, if seen from side, with 

 rounded convex upper posterior margin; from the base of this end 

 portion arise, below, two slender appendages, which are curved 

 nearly in a knee-shaped manner, if seen from side; these processes 

 are shorter than the upper lobes. Length of body, 6.6 mm. 



Remarks. — In the structure of the tenth segment, and partly of 

 the penis, this species is similar to Hydromaniciis jrater Ulmer, but 

 in the structure of the inferior appendages, and of the lateral 

 processes of the tenth segment, which are very long and slender, it 

 reminds one more of Hydatopsyche inelli Ulmer. In the anterior 

 wings the subcosta is confluent apically with R, as in inelli^ but the 

 short, common portion ends not on Rsi, but on the anterior margin, 

 close to Rsi. Discoidal and median cells as in Hydrornanicus frater, 

 but the third fork begins earlier, and M2 and M3 are connected by a 

 cross vein as in Hydatopsyche vielU. Thus intemiedius is really an 

 intermediate form between these species, proving that the genus 

 Hydatopsyche Ulmer is very closely allied to Hydronianicus frater 

 Ulmer with its allies, and perhaps may be united with it. 



rype.— Male, U.S.N.M. No. 43155, from between Mount Omei and 

 Mount Wa, Szechwan (2,000 to 8,000 feet), 1922. 



Specimens examined. — One, the type. 



