1903.] 



115 



poi'tant). Their apices are always sharp and somewhat incurved ; and on the inner 

 side of this tooth-like or rather horn-like termination is generally another somewhat 

 similar process, either sub-adjacent to it and running more or less in the same 

 direction, or projecting from it nearly at right angles, running therefore not alongside 

 of but away from it. In tlie latter case it is often very difficult to sec the interior 

 process at all ; it gets foreshortened, or hidden away among the hairs, &c. The 

 presence or absence of the former condition, however, can generally be recognised 

 pretty easily after a little practice, by examining the claw with a fairly strong lens, 

 holding it meanwhile in two or three different positions against a lighted background. 

 When the apex of the claw and the process are adjacent and subparallel, the claw 

 is called " bifid." In the other case it is said to have a " subapical tooth." But 

 the distinction is not always so well marked as in the following figure. 



Fig. 8. 



a, Claw (bifid) of a Pamphilius. b. Claw (with subapical tooth) of a Lyda. 



7. Tliomson makes a good deal of use of the " xiarajpsides," i. e., the dividing 

 furrows between the middle and side lobes of the mesonotum (as to their " dilata- 

 tion behind," &c.). Personally, I must own, I have not found these characters 

 helpful ; but others may do so. 



8. Puncturation, and the finer sculpture (generally) of all parts of the body, 

 including the pleurm, are most important for specific determinations. 



9. In many females the form of the saw-sheath, viewed both above and from 

 the side, gives excellent characters. Care should be taken never to obliterate or 

 conceal these characters while "preparing" specimens, especially Doleii>.;es and 

 Nematides. Also in determining Tenthredopsis species, both male and female, and 

 in many other genera, the ventral side of the abdomen requires most careful 

 examination. 



10. An important thougli minute structural character, first, I believe, em- 

 FlG. 9. ployed by Thomson and since by Konow for arranging the 



^^;r'^r^;:j^rr- Bleiinocampides, is the following. In some genera the me- 



^^ sosternum (or mesopleura + mesosternum, for in these cases 



Xy- "^*^ j-jjg (^^Q ^j,g hjjr^jiy iq bg distinguished) is simply convex 



TM'iosUxrui.m ^''o^i*' "P ^'O ^'^c sulcatui'e, which sepai'ates it from the pro- 

 thorax : in others that part of it which is adjacent to the 

 prothorax is abruptly depressed and separated from the 

 remaining area by a definite sulcus, as in fig. 9. According 



•, , ,u ^,,_ to the presence or absence of this latter cliaracter a meso- 

 • hrae^OiTtKirn ' . . ,, 



thorax is said to have or not to have distinct "praestema 

 Mesothorax uraiier/us* , , ,. , m, x 



discrctis of a Tomoste- (vrcesterna discreta, Ihoms.). 



thus (lateral view). 



11. The outline of the scutellum, its greater or less gibbosity, and the manner 

 in which it is divided from the mesonotal " lobes," occasionally have to be examined, 

 as well as in many cases its puncturation. 



* The " praestemum " is diagramatically shaded, therefore more conspicuous than in nature. 



