ORTHOPTERA OF NOVA SCOTIA. — PIERS. 339 



is. only one native species, G. assimilis, in the whole of America, 

 then such keys as this, or better ones to Pjeplice them, may 

 be of service as indicative of prevailing phases or variants. 



Key to Native Forms of Gryllus in Northeastern America.* 

 (After Dr. E. M. Walker.) 



Black, wing-covers and parts of body sometimes dull reddish-brown; first 



joint of antenna" not projecting beyond front of head. 



a. Ovipositor nearly or fully half as long again as hind femora, usually 



exceeding 16 mm. [Blatchley and Weldon say exceeding 18 mm.l 



in length; male stout, with large and broad head. [Not yet reported 



from Nova Scotia] abbreviatus 



aa. Ovipositor rarely more than one-fourth as long again as hind 

 femora, seldom if ever more than 14 mm. or less than 12 mm. 

 [Blatchley says 13-14 mm.) in length; male more slender, with 

 narrower and less swollen head 28. pennsylvanicus, p. 341. 



Both of these forms are dimorphic as regards length of wing, being termed 

 short-winged or long-winged, the former being the usual variety. 



We should now consider the views of still later writers 

 on these vexed points of difference. Rehn and Hebard (1915) 

 in writing of the variants of their all-embrasive G. assimilis, 

 caution us that the characters intermingle in every way and 

 are in no case fixed, so that in their opinion the use of special 

 names to designate the variants is not at all warranted. These 

 wi iters, however, present the leading characteristics of 

 the variants most frequently encountered and which have 

 hitherto been designated by names. Colour, length of wing- 

 covers and wings, and general size are the only peculiarities 

 considered, other metric comparisons being discarded. The 

 unstable characters of variants occurring in the northeastern 

 and northern regions are compiled as follows from symbolic 

 formulae given on page 302 of their paper. These characters 

 will hardly bear drafting into a formal key. Their remarks 

 on distribution and intergradation are also given. It may 

 be noted that females, as a rule, have the tegminal and 



♦The European House Cricki-t, Grytlun domenticua Liniueus, an introdured species, 

 is said to occur in the United States and Canada east of the Great Plains. It has been reported 

 from Toronto (E. M. Walker) and Montreal, and is said to occur sparingly on the southern 

 borders of New England, but has not been found in Nova .'"cotia. It is distinguished from 

 native species by being straw-coloured, marked with brownish on head and thorax, and by 

 the first joint of the antenna projecting slightly b<'yond the front of head. It may possibly 

 occur about old stone fireplaces in rural districts. 



