SUBFAMILY I. TETRIGIXvK. 161 



of doubt, as they formed a part of the W. W. Saunders collection 

 purchased by Mrs. F. W. Hope and presented by her in 1873 to 

 the University Museum, Oxford, England. They were labelled 

 briefly "Amer. b.," which R. Shelf ord. Curator of the Museum, in- 

 terpreted to Hancock as "North America." Dr. Hancock states 

 (Ms.) that they are "probably from the eastern part of Canada in 

 the neighborhood of Hudson Bay, judging from other material 

 examined at the same time." A brief comparative diagnosis of 

 the species is therefore included as follows: 



( ). NOMOTETTIX VALIDTTS Hancock, 1909, 415. 



Stouter than N. cristatus. Dark gray, the median crest of pronotum 

 in the type dull yellow. Vertex with front margin obtuse-angulate, more 

 strongly produced in front of eyes than in cristatus, its median carina 

 slender, more elevated, continuous with the frontal costa, the latter not 

 excavated or concave between the eyes as in cristatus, its branches narrow, 

 distinctly divaricate, nearly as much so as in Neotettix. Pronotum with 

 front dorsal margin more obtuse and less produced forward than in cris- 

 tatus. Median carina lower and less arched than there; posterior process 

 acute, reaching almost to tips of hind femora; tegminal sinus almost ob- 

 solete, lower one wide, rather deep, the lobe between them evident only as 

 a convexity of the hind margin. Length of body, short form, 9, 11; of 

 pronotum, 8.8; of hind femora, 6.5 mm. Long form, length of body, 9, 13; 

 of pronotum, 11.5; of hind femora, 5.5 mm. 



Two females, with origin as above given, were described by 

 Hancock. I consider his N. arqticus only the long form of validus. 

 The body is more slender, but the characters of vertex, frontal 

 costa, etc., are the same. 



II. ACRYDIUM Geoffrey. 1704, 300. (Gr., "a locust.") 

 This genus, which replaces Tctri.v Latreille (1802), (Tettir 

 Charp., 1841 of most authors), comprises those grouse locusts 

 having the vertex wider than oue of the eyes, and distinctly pro- 

 duced in front of them (Figs. 2b, 3), its front margin either sub- 

 acute, subangulate or rounded, carinate at middle ; antenna? often 

 shorter than head, 12- to 14-jointed, never reaching the shoulders ; 

 pronotum more or less rugose-granulate, with median carina usu- 

 ally distinct but not arched or raised as in ~Xo>notrtti,r, front mar- 

 gin truncate or feebly angulate, posterior process acute, very often 

 abbreviated, the apex reaching the end of abdomen in short forms 

 and usually extending much beyond it in long ones of the same 

 species; hind femora swollen but more slender than in Xoinofcttix; 

 hind tibia? feebly enlarged near apex, their carina? short, spinose; 

 first joint of hind tarsi distinctly longer than third. 



