( ixvi ) 



tbe only species with one pair of hindtibial sinirs not belonging to tliose groups 

 being a member of the Pliilitrnpelinte (Micro.yj/iiii.r). 



We agree with Kolbe in consiilering the spurs to be modified spines ; 

 they are morphologically homologous with hairs, but they are spines with a 

 matrix of their own which develops scales, hairs, and spines giving the mid- 

 aud hindtibial spurs the same covering as have the tibiae. It sounds curious 

 that we are speaking here of a scaled and hairy hair, but it is nevertheless 

 correct. We refer the reader to anotiier instance where au ordinary spine has 

 developed into a scaled organ similar to the spurs. One of the ventral rows 

 of siiines on the tarsns is in some Si/ntomidae more prominent ; the spines are 

 longer and stonter than ordinarily, and are densely scaled ! 



There are normally four ventral rows of spines ou the tarsus of 

 Lepidoptera. The regnlarity of these rows is very often disturbed by inter- 

 mediate spines, or by the disappearance of spines. A remarkable development 

 commonly found in Soctiiidae. Arctiidae, Ai/arixtidae, Sipitomidae, Coci/tia, etc., 

 but not met with in Sjd////c/idae, is that in which the two inner rows merge 

 together into one, so that there are apparently only three rows. In Zijgaenidae, 

 Lasiocaiiijjidac, some deometridae and Notodontidae the ventral spines are very 

 numerous and arranged in more or less regular transverse series. The lateral and 

 dorsal sides of the tarsus are also spinose ; the latter spines of the compressed 

 mid- and hindtibiae, for instance, are very numerous. The anterior tarsns 

 shows difierent modifications in the spines from the raid- and hiodtarsi. The 

 external row (or row 1) of the foretarsus contains often some long spines 

 (PI. LXIV. f. 1 — 5) ; not rarely these long spines alone are present and are 

 enlarged to curved claws, there being generally present three such spines on 

 tiie first segment, and one special one on the following (PI. LXIV. f. 5). In 

 most cases the long sjjines are accompanied l)y some small ones, generally 

 placed near the base of the segment. Such claws as these are commonly found 

 in Ac//froiitii/!'tf', accompanying other modifications (reduction of mouth-parts, 

 spinosity of tibiae, etc.) ; they are wholly absent from all other Spldnqidae except 

 Clioerocampiixw, where they occur occasionally in a lesser degree of development. 



Another modification obtains in Coci/tiiis. In this genus of Acheronfiinae, 

 especially in tlie males, the fourth row of the foretarsal segments resembles a 

 short-toothed comb or rake, the spines standing rather close together and being 

 directed ventrad and somewhat cnrved (PI. LXIV. f. 6). The spines of the other 

 rows have, in some species, disappeared for the greater part (PI. LXIV. f. 10). 



The foretarsal spines of Vephonodes are mostly reduced to hairs. 



The midtarsal spines have also their specialisation. Here it is the fourth 

 row. The basal spines of this are prolonged to long bristles (PI. LXIV. f. 7), 

 forming the midtarsal comb alluded to very frequently in the body of this 

 Revision. The comb is very strongly developed in Cocytius, Frofoparce, and 

 other Aclierontiitiae, and gradually disapj)ears (as a comb) in the weaker 

 members of the subfamily, the bristles assuming the normal length. In 

 Ambuliciiiiic it is not met with, not even in forms with such long legs as are 



