OKTHOPTERA OF NOVA SCOTIA. — PIERS. 241 



subgenital plate (that is, the extremity of the under portion 

 of the last abdominal segment) in both sexes. It thus 

 does not include such appendages as the ovipositor, anal 

 bristles, or antennae. The length of the ovipositor is taken 

 from the ventral apex of the basal plica, or fold, to the ex- 

 tremity of the ovipositor. In making careful measurements 

 it will be found most convenient to use fine spring dividers 

 with screw adjustment, operated by a milled wheel between 

 the legs of the instrument, which wheel is easily turned by 

 one of the fingers. Strong hand lenses, and on rare occasions 

 a compound microscope, are required for examining specimens 

 in detail; but for general examination and for use when 

 making measurements, I find by far the most convenient 

 arrangement is an ordinary spectacle lens, of three inches 

 focus, or stronger if desired, mounted in the right-hand side 

 of a common spectacle frame, which may be very cheaply 

 obtained at any optician's. This leaves both hands entirely 

 free for manipulation, which is a very great convenience; 

 and the left eye maj- be used for normal vision when desired. 

 Such a lens I have found of the very greatest service in much 

 general biological work, whenever it is necessary to use both 

 hands and a low-power glass is suitable. Strange to say, I 

 have never found this simple and remarkably convenient 

 device mentioned by any writer. 



Desiderata. — We require further data regarding the 

 occurrence and abundance of species in Cape Breton Island; 

 regarding which too little is yet known. Until fuller informa- 

 tion on these points is available, we will not be able to deal 

 as definitively as we would wish with the Orthoptera of 

 Nova Scotia as a who'e, for very likely a few species do not 

 extend their range into the northern portions of that island. 

 Howevei, this is merely a matter bearing on local distribution 

 and relative abundance, for it is not likely that unrecorded 

 species will be found in that region. These we would rather 

 expect from our southern and western districts. The high- 



