134 PROCEEDINGS OF THE ACADEMY OF [April, 



not exhibit the fluctuations in pronotal structure that A. arenosum 

 angustum does, there being no exact parallel to the type occurring 

 in the latter race to which Hancock gave the name gibbosus. There 

 is no valid reason for recognizing the latter condition by name, 

 unless one is naming what are at most but formative saltations. 



As a considerable portion of the references given for this form are 

 based wholly or in part on individuals of A. arenosum angustum, it is 

 at present quite difficult to mark off definitely from the literature 

 the areas occupied by the two forms, but from the material in hand 

 we can say that at least as far northward as Charlotte, Wrightsville 

 and Lake Waccamaw, North Carolina, the specimens are arenosum 

 arenosum, the Raleigh individuals being intermediate, as is the case 

 with a female from Cedar Bluffs, Nebraska, while the Stone Moun- 

 tain representative shows a tendency toward A. a. angustum, although 

 nearer the southern form. 



The material collected by us was taken on sandy shores (Lake 

 Waccamaw), on a sandy spot at the edge of a bog (vicinity of Stone 

 Mountain), on wet clay along a "branch" in pine woods (Charlotte) 

 or on dry, sandy soil in open forest of short-leaf pine (Wrightsville). 



Acrydium arenosum angustum (Hancock). 



Maryland. North Carolina. 



Laurel, V, 6, 1911, (E. B. Marshall), Tr yon, V, 18, (W. F. Fisher), 19, 



1 d\ [U. S. N. M.]. [U. S. N. M.]. 



Plummer's Island, IX, 29, 1912, (H. L. Tennessee. 



Viereck), X, 13, 1912, (J. D. Hood), rjhrksvillp TTT 31 1909 IV «,nd 17 



1 <? , 1 9, [U. S. N. M. . S Voii'/c p n' u ' 



Washington D C ( \ N C udell) a 19H> (°. F. Crumb; on 



i^i m a m tu i ' ' a tobacco seed bed and hibernating 



Ltf, IU.B. IN. M.J. [HI) 19] in leaves)> 2 ^ g 9j 



Virginia. [U. S. N. M.]. 



Glencarlyn, IV, 27, 1913, (A. N. Georgia. 



Caudell), lcf, [U. S. N. M.]. Clayton, 2,000 feet, V, 18-26, 1911, 



Washington, VI, 5, 1909, (A. K. (J. C. Bradlev), 2 <?. 



Fisher), 1 a\ [U. S. N. M.]. Black Rock Mountain, 2,000-3,500 



Luray, IX, 2. 1906, (F. Knab), 1 9, feet, V, 20-25, 1911, (J. C. Bradley), 



[U. S. N. M.]. lcf. 



For comments on this form see above under Acrydium a. arenosum. 

 We are using the name angustum in place of the synonymic but gen- 

 erally used obscurum, as angustum has page priority. The above 

 north Georgia localities are the most southern from which we have 

 examined the race. In general character the Clayton and Black 

 Rock Mountain specimens are similar to Asheville individuals and 

 all have the pronotum caudate. The Tryon specimen is equally 

 typical of this race, but the Clarksville, Tennessee, individuals show 

 some little tendency toward arenosum arenosum. 



