24 



U.S. NATIONAL MUSEUM BULLETIN 24S 



POSTHUMOUS 



Measurements are given in the tabulation below. 



T. leucolaema T. leucolaema T. melanonota T. melanonota 



& 



& 



Trichodomedea melanonota, new species 

 Figures ii:5-8 



Holotype male, allotype female, and one paratype from Odontophorus 

 melanonotus Gould collected in Ecuador (in USNM). 



Diagnosis: One of the smaller species of the genus. Much less sexual 

 dimorphism in shape of the head than usually found in the genus. Sides 

 of head quite straight from frons to temples. Cephalic index of frons and 

 temples 0.75:1.25 for the male and 0.96:1.50 for the female. Unfor- 

 tunately, tip of the distal abdominal segment of the male is broken off so 

 that little more than half remains, but the structure of the basal portion 

 decidedly differs from other species in the group. The head in the female 

 is more triangular with wider temples; the distal abdominal segment near 

 that of hyperythra, but differs slightly. 



Measurements are given above. 



Trichodomedea dendrortyx suhsimilis, new subspecies 



Figures n:9-12 



Holotype male, allotype female, and one paratype from Dactylortyx tho- 

 racicus (Gambel) collected by W. B. Heed in Tamaulipas, Mexico, May- 

 June 1949 (in USNM). 



Diagnosis: The specimens are overcleared, so some characters are ob- 

 scure and some setae are missing. However, the general shape and mark- 

 ings of the head and body show differences in size sufficient for subspecific 

 separation from dendrortyx. When specimens in better condition can be studied, 

 other differences may be found, especially of the genitalia and distal ab- 

 dominal segment of the male. Five small setae are on each side of the 

 female claspers that are absent in dendrortyx. Other differences in structure 

 of the distal abdominal segment of the male are evident. The cephalic 

 index of the head is very different: in the male of subsimilis it is 0.73 : 1.18 

 and 1.10 : 1.25 in the female. In the male of dendrortyx it is 0.80 : 1.25 and 

 0.90:1.20 in the female. The index given in the original description of 

 dendrortyx is incorrect. 



