

64 Mr. D. Sharp on the 



forms. Some of the older entomologists appear to have 

 sui^ijosed, indeed, that the insects forming this suhfamily 

 were more allied to the Di/tiscid(e and Gyrinid(e than to 

 the CarahidcB, but detailed investigation has not sup- 

 ported this view, and the only position that can be 

 correctly assigned to the Pseudomnrphini in the present 

 state of our knowledge is that given them by Dr. Horn, 

 and already j^reviously indicated by Duval (Gen. Col., 

 Camhidcs, p. 47). There is, however, a question with 

 regard to the group that has not, so far as I am aware, 

 been j^et investigated, viz., whether any approximation 

 exists between the group and the Panssidce ; and I men- 

 tion this as an interesting subject for inquiry. 



The family Carahidce is at present composed as 

 follows : — 



75 species = 5 genera = (? 2) tribes = Pseudo-\ 



mnrpliince . 

 8000 species = 500 genera = ("? 31) tribes = 



HarpaliiKe. 

 1800 species = 100 genera = 15 tribes = Cava- 1 Sj 



Unce. ^ 



d s'pecies ^= Mor7nolyce. . . . ./ 



It will, I hope, be understood that the above tabulation 

 is merely an approximation to the actual numbers, but 

 it will be found sufficiently near the mark to allow us to 

 detect some interesting statistical facts. Thus the 

 average number of species to a genus in each of the 

 three subfamilies is very nearly the same, being 

 respectively 15, 16, 18 ; on the other hand, the average 

 number of genera in each tribe is extremely different, 

 being respectively 2*5, 16, and 6*75. I shall here con- 

 tent myself with pointing this out, and refrain from 

 entering on any speculations about it. As regards the 

 number of tribes, or aggregates immediately subordinate 

 in complexness to the subfamil}^ I must however remark 

 that their number is quite uncertain, and will probably 

 prove to be considerably greater than that given by Dr. 

 Horn, and approximately adopted above, for Dr. Horn's 

 studies have been made chiefly on the North American 

 forms, and the vast mass of exotic forms unknoAMi to 

 him would probably cause a considerable increase in the 

 number of these tribes. No doubt also much additional 

 consideration as to the limits and afltinities of those 

 proposed by the American writer will be necessary before 



