T. D. A. COCKERELL. 89 



Note. — Allied to M. mysops is 31. desponsiformis Ckll., from 

 Oregon. The following table separates this species from several of 

 its allies. 



Cheeks witli black or sooty hair 1. 



Cheeks with yellowish white or greyish white hair 2. 



1. Abdomen without hair bands; middle of mesothorax strongly and closely 



punctured ciiici Rob. 



Abdomen with pale hair bauds on segments 3 and 4, and a line on each side 

 of 2; middle of mesothorax shining and rather sparsely punctured. 



despoiisiforiniM Ckll. 



2. Dorsum of thorax with a good deal of black hair; inner orbits pai-allel. 



mysops Ckll. 

 Dorsum of thorax without black hair; inner orbits diverging above. 



gleiiwoodensis Ckll. 

 Group N. 



Last two segments of abdomen with the hair not, or not all (excluding extreme sides) 

 black or fuscous. 



Thorax above with some black hair 1. 



Thorax above without black hair Group O. 



1 Small species; abdomen beyond first segment covered with fulvous tomentum. 



i^lelissodes pi iis^iiis Cress. 

 Eather large; abdomen beyond middle of second segment covered with orange- 

 fulvous hair Xenoglossa exqiiisifa (Cress.). 



Not like either of the above 2. 



2. Fifth abdominal segment with black hair, the sides with patches of white 



tomentum Florilegiis coiidigna (Cress.). 



(Compare here also Tetralonia donata (Cress.), which has the fifth abdominal 



segment with black hair, but apical margin narrowly fuscous; a small 



species of Mexico, not quite 9 mm. long.) 



Larger; fifth abdominal segment with brown or purplish brown hair, and no 



lateral patches of white tomentum 3. 



3. Mesothorax with hardly any black hair; tegulse light apricot color; very large 



species; eyes light green; fourth abdominal segment without a dia- 

 mond shaped (or any) nude area M. heliantlielli Ckll. 



Mesothorax with much black hair ; tegulae darker 4. 



4. Smaller; eyes strongly yellowish (or may be yellowish grey); flagelium 



darker; abdomen more pubescent, segments 2 and 3 with very broad, 

 entire, ochreous hair bands, covering apical margins. 



Ifl. siiflTiisa Cress. 



Larger; eyes plumbeous; flagelium clear red beneath, except the two basal 



joints; abdomen less ])ubescent, fourth segment with a diamond 



shaped nude area; segments 2 and 3 with oblique lateral stripes of 



hair, the apical margins bare W. conianche Cress. 



Note. — M. sujfusa has a good deal of superficial resemblance to 

 Tetralonia frater aragalli, but it is a true Melissodes, as shown by 



TRANS. AM. ENT. SOC. X.XXII. (12) JANUARY, 1906. 



