224 [February, 



hns been guided by what he conceived to be the highest principle applicable to each 

 particular ca'?e. This is good practical common sense, and we agree that, in the 

 present state of the science, this is all that could be done. Such is the deficiency of 

 our knowledge tliat in some of the larger genera Mr. Marshall has been driven as a 

 last resource to an alphabetical arrangement of many of the species ; for instance, out 

 of twelve dozen species of Ichneumon, the last three dozen are given alphabetically, 

 and out of 61 species of Tryplion only 13 are classified, which it is presumed must 

 be taken as an indication that little or nothing is known of the residuum than that 

 somebody has published certain names with descriptions, or has announced in some 

 periodical or other the capture in Britain of certain continental species ; they remain 

 to be re-discovered by the Hymenopterist of the future, or perhaps to be shewai up 

 as only old friends under different names. 



In the selection of citations and references to authors, Mr. Marshall had a 

 difficult task to know where to draw the line, in order to keep the Catalogue within 

 reasonable bounds. In this portion of his work, Gravenhorst would probably be at 

 once his greatest aid and his greatest difficulty. So far as the reviewer can judge, he 

 has acquitted himself of this task with admirable discrimination, his aim havhig 

 been to " exclude all matter so doubtful as to be useless, and to render the references 

 complete in all cases of certainty." In some cases, perhaps, exclusion might 

 advantageously have been carried further; but, on the whole, inclusiveness, if a 

 failing, is a failing on virtue's side. 



The disproportion between the number of genera, as compared with the number 

 of species, in the Braconidce and Ichneumonidce, can scarcely have failed to be obseiwed 

 on reading the first paragraph of these remarks. The 439 species of Braconidce have 

 been divided into 125 genera, only 11 fewer than the number which suffice for the 

 1186 species of Ichneumonidce. As Mr. Marshall points out, this disproportion is the 

 result of a totally different idea of Genus in different minds, and is mainly due to 

 the labours of Forster. If the Ichneunionidcs were handled by a Forster as the 

 Braconidce have been, the 136 genera of our List would become 336 at least. To 

 the specialist or student who limits his range of observation to a single group of 

 comparatively small extent, this multiplication of so-called genera is attractive and 

 convenient ; but it may well be doubted whether it is an advantage to the general 

 student, whilst many will think that it is a degradation of the genus, and that the 

 characters upon which the minute sub -division is based are not generic characters at 

 all. But this is too wide a subject to pursue on the present occasion. 



In conclusion, I have to congratulate Mr. Marshall on the completion of his 

 tedious task, tlie Society on having found so able and willing a workman, and British 

 Entomologists generally on the f^ict that the Society by Mr. Marshall's aid has been 

 enabled to place within their reach a Catalogue of this extremely interesting group 

 of insects. This List ought to be a starting-point for many discoveries, for new 

 species may be found everywhere, if collectors will only take the trouble to capture 

 them. Entomologists who care not for Hymenoptera may do good service ; too 

 freqiiently for the realization of their hopes, our Lepidopterists make the acquaintance 

 of parasitic Hymenoptera ; and, if it be too much to expect that they should them- 

 selves devote a little attention to their persecutors, they might at least transfer them 

 to Mr. Marshall, who would not consider them beneath his notice. 



One word as to the futm-e. It was understood some time ago that the Ten- 

 ihredinidcB stood in the way of an early completion of this Order ; but after the splen- 

 did instalment that last year has produced, may it not be hoped that arrangements 

 have been made to finish the Catalogue of Hymenoptera in 1873 ? — J. W. Dunning, 

 Lincoln's Inn : January, 1873. 



