T. D. A. COCKKKELL. 75 



Series 2. — Labrum black. 

 Antennae very long, entirely black, strongly crenulate. 



Tetralonia hirsiitior (Ckll.)- 

 Antennaj with flagellum fulvous or ferrugiuous beueath • . • ■ j^Ielissodes spp. 



In Entomologist, July, 1902, p. 177, I have given a table to 

 separate the species of Melissodes falling in this series ; since then 

 one species {31. semitristis Ckll., from Arizona) has been added. 

 The following notes will be useful : 



M. tristis Ckll. Mandibles with no yellow spot. 



M. sphceralcece Ckll. Mandibles with a yellow spot ; sides of 

 apical part of abdomen with three teeth, but middle tooth not 

 nearly as large as in intorta. 



M. intorta Cress. Antennae not half as long as in tristis; hind 

 margins of abdominal segments narrowly dull white; three teeth on 

 each side of apical part of abdomen, the middle one very large, and 

 peculiarly formed ; paljri seem normal for Melissodes ; abdomen 

 not banded. 



M. personatella Ckll. Antennae very long ; flagellum ferruginous 

 beneath ; mesothorax with black hair. Length 10 mm. 



M. semitristis Ckll. Stature of M. menuacha, but black clypeus 

 and broader face of tristis. 



The two following species are not strictly of this group, but they 

 should be compared with it : — 



M. prcelauta Ckll. Looks like semitristis, but clypeus greyish- 

 white, face narrowed below, eyes black, pubescence pure white on 

 head and mesothorax (Arizona). 



31. hexacantha Ckll. Also from Arizona. Clypeus black with a 

 yellow band in front ; antennae not nearly so long as in tristis ; lat- 

 eral spines of end of abdomen six ( instead of the usual four). Diflers 

 at once from Xeiioglossa angelica by the black tegulae, and scuttellum 

 with black hair ; by the same tokens it also differs from X. pruinosa. 



31. he.vacantha is quite variable, as follows : — 



Var. a. — Thorax at)ove without black hair, except half a dozen or less on meso- 

 thorax ; hair of abdominal segments 5 and 6 black. 



Var. b. — Lower half of clypeus yellow, and a yellow process directed upwards in 

 middle line. 



Var. c— Yellow of clypeus much redu(red. 



Group B. 



Clypeufi light ; labrum dark, wholly or partly. 

 (In intrudens, snowi. dentiventrix and vernonensis the labrum has a large yellow 

 or light spot.) 



TRANS. AM. ENT. SOC. XXXIf. JANUARY, 190G. 



