CHARLES W. METZ. 113 



show much less variation than those of P. cressoni, but this 

 is very likely due to the smaller number of specimens. In 

 thoracic and leg markings they vary just as much : many 

 specimens having practically no yellow on collar, tubercles, 

 or tegulae, which condition is usually accompanied by a reduc- 

 tion to some extent of the face markings, such as the loss of 

 the swollen apices of the lateral face marks. The extreme 

 specimens of this kind I have considered identical with 

 Cockerell's " P. digitatus ", and have called "form digita- 

 tus " as described above. This was described as a distinct 

 species with a number of varieties, or races, (Ckll. Psyche 

 Supp. 7:30), but undoubtedly they are merely poorly pig- 

 mented specimens, corresponding to the form " saniculae " 

 under P. cressoni. The same tendency toward poor pigmenta- 

 tion is found in a number of species, but other characters 

 such as genitalia, sculpture, etc., prove their specific identity 

 with the better colored forms in each case. This is made 

 especially evident from the fact that no two of these speci- 

 mens agree in the poorly developed marks, some having one 

 part and some another more fully developed. A series illus- 

 trating this in the case of P. cressoni is shown in figures 

 81-83. This variability accounts for the various specimens 

 described by Cockerell as races. 



Under " variety bakeri " I have included specimens of the 

 type described by Cockerell as P. bakeri. A specimen of 

 this in the C. F. Baker collection is very distinctly marked, 

 as described, but other forms show such a tendency toward 

 the markings of this form that specific distinction is un- 

 warranted, especially in such a species as this in which a 

 considerable range of variation in marking is found, and 

 since the genitalia are identical with those of a large series 

 of typical specimens. 



The insufficiency of the characters upon which the forms 

 and varieties described as species, P. bakeri, P. digitatus, P. 

 ruidosensis, and P. riidbeckice race siibdigitattcs, were based, 

 can be seen from the following key given by Cockerell for 

 separating them : 



TRANS. AM. ENT. SOC, XXXVII. (15) 



