178 THE entomologist's record. 



around London than in an}^ part of England that I have visited. In the 

 City of London Society's " ten-mile list," Dr. Buckell tells me that it is 

 recorded as occurring over the whole area, so that it seems to have as 

 much right to a place among the special London fauna as Biston hirtaria, 

 sparrows, pigeons or cats. 



Structure of the Imago. — In this the genus differs widely from 

 the rest of the Sph'ngidae, the following being some of the more notice- 

 able points of difference. The fore-wings are ampler, the hind margin 

 generally irregular and sometimes dentated ; the head and eyes are 

 very small ; the antennae are soft and flexible, are more or less 

 pectinated, especially in the males, and taper slightly towards the tip. 

 The tongue is very short, and is even said to be entirely wanting in 

 S. q^tercus. In place of the firm and elegant bodies which are usual 

 among the Sphinx moths, the bodies of this genus are soft and blunt, 

 and, in the females, very bulky, and remind one forcibly of the larger 

 Bombycids. To this group they also present affinities, though 

 probably only superficial ones, in nearly all the above-mentioned 

 chairacters, as well as in their great egg-laying capacity and in their 

 tendency to " assemble." Perhaps the similarity of their habits would 

 largely account for these points of resemblance, though both Mr. 

 Poulton and Professor J. B. Smith (of Washington) seem to be of 

 opinion that there is a true relation between Sphlngidae and Bomhycidae, 

 and I believe Dr. Chapman considers that Smerinthns is related to 

 Notodonta. 



The relation of the genus to allied Genera. — As to the position 

 which Svierhithtis occupies in relation to the other genera of the family, 

 opinions differ. Stainton, Barrett and Newman place it just before 

 Aclierontia, while it is placed just after Choerocainpa by Kirby. Mr. 

 Poulton says that in their younger stages Smeriiifhus and Sj'hinx Jiijnstri 

 are very near together ; they certainly have many characters in 

 common. S. Jignstri, in its first skin, has forked hairs, though these 

 are black, and are thinly scattered comjDared with the " door-mat " 

 appearance which is characteristic of Smerinthus. The shape of the 

 head is similar to that of *S'. tiliae in its earlier stages, and the pupai 

 are also somewhat alike. In the imagines, however, the only points of 

 resemblance that I can see are that the head and eyes of »S'. lignstri are 

 small, and that the antennae are somewhat similar in structure. On the 

 other hand, the resting-position is quite different ; S. lignstri, like 

 A. atrojws, S. conrolcidi, etc., resting with the fore-wings sloped over 

 the back and the hind-wings folded underneath them. The resting- 

 position of Choerocampa is similar to that of Smerinthns, but the pupse 

 are very different. Whatever may be the right jjlace for Smerinthus, I 

 can see no reason for putting A. atropos next to it ; for I think that 

 without question S. ligustri is a nearer relation, and it is probably a 

 link between the two. Turning to individual differences, the hind 

 tibiae of S. tiliae have four spurs, while those of the other species have 

 only two. I find that A. atropos, S. ligustri, C. elpenor and M. fuci- 

 formis also have four spurs to their tibiae. The males of >S'. tiliae have 

 a frenulum, but in the females this is only rudimentary, the loop being 

 entirely absent and the bristle being rej^laced by a number of short 

 slender ones which are of no apparent use. The males of *S'. ocellatus 

 possess a small bristle, the females a group of small ones, but there is 

 no trace of the loop in either sex. I examined a number of specimens 

 of S. popidi, but could find no trace of loop or bristle in either 



