PROC. ENT. SOC. WASH., VOL. 20, NO. 9, DEC., 1918 207 



a median pit; antennae reaching metathorax; flagellum very obscurely 

 brownish beneath, the middle joints much longer than broad; cheeks and 

 front with long white hair, face with black and yellowish white mixed; 

 hair of mesothorax grayish-white and black mixed, of scutellum black, of 

 posterior part of thorax white, of sides of thorax grey, with a patch of 

 black on mesopleura; mesothorax and scutellum shining, with sparse and 

 rather small but distinct punctures; area of metathorax with a very strong 

 transverse keel, above which are about six enclosed quadrangular shining 

 spaces; posterior face of metathorax polished in middle, but coarsely rugo- 

 sopunctate laterally; tegulae black; wings conspicuously brownish; second 

 submarginal cell very broad, receiving first recurrent nervure about the 

 middle; legs black, the tarsi reddish apically; abdomen with the first two 

 segments smooth and shining, but the others with a very fine but evident 

 sculpture; under the microscope the first segment is seen to have very 

 sparse and minute piliferous punctures, the second has closer piliferous 

 punctures, but the third has a minute transverse striation; first segment 

 with long white hair at sides; segments 1-5 with apical white hair-bands, 

 falling in middle of first. 



Zaruma, Ecuador (Frank W. Rohicer), one, collected August, 

 1915. Apparently the only Colletes previously recorded from 

 Ecuador is C. rutilans Vachal, a species with bright red hair on 

 head and thorax. C. rohweri resembles C. intermixtus Swenk in 

 the broad hind basitarsi, but the hind tarsi are much longer, and 

 the spurs are normal. I do not know any very closely related S. 

 American species; it is very distinct from those I have seen from 

 Peru, and does not agree with any Central American or Brazilian 

 form. Type in the author's collection. 



Actual date of publication, April 22, 1919 



