184 T. D. A. COCKERELL. 



More or less green or purple forms, confused with Megacilissa, be- 

 long to Ptiloglossa Smith, which in Ashmead's tables is placed with 

 Andreninse. 



MYDROSOMA.Smith. 

 Ashmead has it Madrosoma; Mr. Vachal pointed out the error. 

 This has an obtuse emarginate tongue, and seems to be a genuine 

 Colletid, differing from Colletes by its metallic tints. In Caupoli 

 cana (C. yarrowi Cresson) the tongue is short, but deeply divided 

 into two long narrow segments, which are thickly covered with long 

 bristles. The labial palpi are short and thick, the first joint very 

 stout and as long as the next two together, the second and third 

 short and cordate, the fourth swollen-cylindrical, and decidedly 

 longer thau the second or third, which are equal to one another. 

 The short six-jointed maxillary palpi have the first joint much the 

 longest, as long as the next three together, 2 to 5 suboval and about 

 equal, 6 long-cylindrical, nearly as long as 4 and 5 together. The 

 galea, though short, is longer than the palpus, and bears long bris- 

 tles at its end. The teeth of the maxillary comb are extremely 

 long. The form of the maxillary comb, with the lower teeth longer 

 and curved, is quite as in Colletes. While Caupolicana is not so 

 like Colletes as Mydrosoma must be, I think there is no question that 

 Ashmead is right in including it with the Colletidse. The form of 

 the palpi is quite suggestive of Scolia. 



PROTOXiEA Ckll. and Porter. 



This is not related closely to the Colletidse. Compared with a 

 Scolia (? /nematodes') from Las Vegas, N. M., the mouth parts show 

 the greatest possible similarity, so that I must regard Protoxcea as 

 derived from the Scoliidse, or rather both from a common ancestor 

 having a similar mouth. The long first joint of the labial palpi of 

 Protoxcea appears to be produced by the chitinisation of the area 

 between the first joint (very short) in Scolia and the mentum, that 

 is, of the palpiger. Thus, the labial palpus represents palpiger and 

 the first joint of palpus fused. Scolia has a marginal comb on the 

 galea, which is lacking in Protoxcea, which has not even the ordin- 

 ary maxillary comb. 



The differences between Protoxcea and the Scoliidse, aside from 

 the mouth-parts, at first sight seem very great, but there are resem- 

 blances which should not be overlooked. In particular I find a cer- 



