14 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 123 



ventral aspect ribbon-like with tip slightly recurved. Aedeagus with 

 a heavily sclerotized apical portion that is enlarged slightly at neck, 

 spiral process wound around neck one-and-a-quarter turns with apex 

 laying along apical portion, basal portion slender. 



Holotype, male: Mexico (Vera Cruz), Cuitlahuac, Aug. 10-12, 1964, 

 Spangler. 



Paratype: Mexico (San Luis Potosi), Palitla, June 5, 1966, Flint, 

 Id*. 



Hydropsychidae 



Diplectrona chiapensis, new species 

 Figure 60 



This is the first species of the genus found in the New World south 

 of the United States. The male may be recognized immediately by 

 the internal sacs in the seventh segment and the shape of the lobes of 

 the tenth tergites. 



Adult. Length of the forewing: male 9-10 mm, female 12 mm. 

 Color pale brown, male with faint dark irrorations on forewings, fe- 

 male with dark marks more distinct. Fifth segment with an antero- 

 lateral process that is slightly longer than segment. Male genitalia: 

 Seventh segment with a pair of large striate internal sacs opening on 

 posterior margin. Tenth tergum divided into trianguloid lateral 

 lobes that much surpass the mesal lobe, dorsally completely divided 

 on midline. Clasper long and terete. Aedeagus obliquely truncate 

 apically, subapically with a complex of internal sclerites. 



Holotype, male: Mexico (Chiapas), Dolores, route 190, km 1190, 

 Aug. 7, 1965, Flint and Ortiz. 



Paratypes: Same data, 5 d\ 3 9. 



Hydropsyche vespertina, new species 



Figures 58, 59 



This species is a member of the H. depravata group. The com- 

 bination of dorsal point and rectangular shape of the tenth tergum, 

 moderately angled base and enlarged tip of the aedeagus will separate 

 this species from the other described species of the group. 



Adult. Length of forewing 9-11 mm. Brown, antenna with dark 

 V-marks on basal segments, wings marked with typical pattern of 

 golden-brown and grey-brown hairs. Male genitalia: Lateral lobe of 

 ninth segment well developed. Tenth tergum rectangular in lateral 

 aspect, with a sharp apicodorsal point, and a shallow U-shaped 

 dorsomesal excision. Clasper with upper surface of basal segment 

 rather sinuate, apical segment terete. Aedeagus with base angled 



