MR. TRIMEN ON MIMETIC ANALOGIES AMONG AFRICAN BUTTERFLIES. .501 



racters of importance. The splendid ftimily FaplUoiudce, Ijy mere force of the size, 

 number, and beauty of its members, has so long held the place of honour in English and 

 in most continental classifications, that many lepidopterists are loth to supplant it by a 

 comparatively insignificant-looking group; but, regarding the question structurally, 

 there can be no doubt that an arrangement which interposed between the only families 

 with fully developed fore legs (viz. the PapUionklce and Fleridce at one end of tlie 

 series, and the HesperiidcB at the other) all the groups that more or less widely diflfered 

 in the character of those very organs was artificial and unnatural. On the other hand, 

 Mr. Wallace {loc. cit. p. 2) has questioned the propriety of claiming a high position for 

 any group on the ground of extreme imperfection of any of its organs. Taken apart 

 from other considerations, this at first sight appears a valid olycction ; but it must be 

 borne in mind, as suggested by Mr. Bates, that tiie Lepidopterous type among Articu- 

 lata, like that of the Bird among Vertebrata, is preeminently aerial, and, consequentlv, 

 that a diminution of the ambulatory organs, instead of being a sign of inferioritv, 

 may very possibly indicate a higher (because more thoroughly aerial) form. Mr. Wal- 

 lace further contends for the first rank being accorded to the Pcqjiliomdce, on account 

 of the perfect insects possessing the peculiar and constant character of an apparently 

 4-branched median nervure, and a " spur"* on the anterior tibite, and the larvae having 

 an extrusible Y-shaped tentacle. The appendage to the anterior tibiae is admitted by 

 Mr. Wallace to be a character of some Sesperiidce ; and not having been found in other 

 Butterflies, it may fairly be regarded, in conjunction with the full development of the 

 first pair of legs, as a sign of affinity, however distant, between the two families. The 

 apparent fourth branch of the median nervui'e is not an additional nervule, but actually 

 the lower radial (" second discoidal nervule" of Doubleday) unusually placed in relation 

 to the third branch of the nervure, and thus cau hardly be regarded as in any way signi- 

 ficant of superior developmentf. Nor can the Y-shaped tentacle of the larva be insisted 



* This is more strictly a small foliated expansion or appendage. 



t More remarkable points in the neuration of the PapiUonidce are the following, viz. : — 1st, the short, transverse, 

 interno-median nervule, uniting the median and submedian nervures of the fore \yings, and closing a small basal 

 cell; 2ndly, the well-marked internal nervure of the same wings, which has an independent course, and terminates 

 on the inner margin ; and, 3rdly, the distinct prediscoidal cell of the hind wings, formed by the junction of the 

 branched precostal nervure with the costal. Papilio (including Oniithoptera) appears constantly to present these 

 characters, with some variation in the size of the prediscoidal cell of the hind wings ; the Australian Eurycus also 

 possesses them all, and ha.s the prediscoidal cell unusully large ; in Seridmis, Tcinopalpus, and Leptocimis appear 

 the internal nervure (but luil the interno-median nervule) of the fore wings and a mneh-narrowed prediscoidal cell : 

 Parnassius and Thdis present only the internal nervure of the fore wings : and in the aberrant Don t Is I can trace 

 none of the three characters. In other families we find the transverse iiitirno-iitrdian nervule in several of the Mor- 

 phidce, thougli not so completely developed ; the Internal nervure is present in the Danaidai, but, instead of having an 

 independent course, is intimately connected with the submedian nervure, and ends by anastomosing with it; while 

 the prediscoidal ceU of the hind wings has hitherto been employed as the distinguishing feature of the curious Bras- 

 solidce, in which it is formed in precisely the same manner as in the Papiltonidiv. 



The presence of adcUtional cells, enclosed by anastomosing nervures, is a feature not rare among the Ileterocera 

 {vide the plates of neuration in Guene'e's * Noctuehtes' and 'Phaleuites' ); and in some genera of Gcometra; {Opo- 

 rahia, Ennomos, &c.) a cell is found at the base of the hind VNings, occupying exactly the same position as in the 

 Butterflies mentioned. 



