370 BRITISH LEPIDOPTERA. 



The specialisation of the antennae, however, is the most 

 characteristic peculiarity of the Sphingid imago. The Amorphic! 

 antenna has an ordinary antennal tip, but in most of the other 

 Sphingids the tip is produced, filamentous, recurved, or otherwise 

 specialised, although, structurally, both are the same. Sharp describes 

 (toe. cit., p. 380) the Sphingid antenna as "having a thick solid 

 appearance, pointed at the tip, which is usually somewhat hooked 

 and bears a few hairs. In the males the antennae are formed in 

 a manner specially characteristic of the family. In section, each 

 joint shows a chitinous process on the underside, forming, with 

 that of the other joints, a continuous ridge, and on each side of 

 this ridge there exists a series of short, delicate ' cilia ' arranged in 

 a very beautiful manner. This structure, with some modifications, 

 appears to be usually present in the family ; it attains a very 

 perfect development in cases where the tips of two rows of cilia 

 bend towards one another, meeting so as to form an arched cavity. 

 This structure is different from what occurs in the J s of other 

 families of lepidoptera, for though cilia are very common, they 

 are usually placed either on two projections from the body of the 

 antenna (instead of on the two sides of a single projection), or 

 there is but a single whorl or set of them on each joint ( Catocala, 

 &c.)." Bodine states that the Sphingid antennae give some considerable 

 colour to the view of a genetic relationship between the Sphingids and 

 ^geriids (Sesiids). He notes (Antennae of Lepidoptera, pp. 36 — 37) that, 

 in spite of Butler's views (Trans. Ent. Soc. Lond., 1878, p. 121) that 

 the antennal structure of the ^Egeriids (Sesiids) was closely allied to 

 that of the Pyralids and Tineids, and not at all to the Sphingids, 

 especially to Hemaris, yet every feature mentioned as being 

 characteristic of the ^geriids (Sesiids) can be paralleled, not only in 

 the Sphingids, but in the genus Hemaris, and that Hemaris thysbe 

 presents the very characters that he describes in Sphecia, except 

 that, in both cases, the " pencil of rigid hairs " is really composed of 

 rigid scales ; the close resemblance in structure and form between 

 the antennae of the yEgeriids (Sesiids) and Sphingids, Bodine considers, 

 certainly points to a genetic relationship. The large compressed 

 ventral expansion, the fusiform or clavate shape, the peculiar 

 distribution of sense-hairs of the third type, the relative size, 

 development, and position of the cones, the tuft of long slender rigid 

 scales projecting from the distal segment, the character of the chitin 

 surface, are all features common to both the ^Egeriids (Sesiids) and 

 Sphingids, and no other forms known at present possess the whole com- 

 bination of characters. The condition of the antennae of the ^Egeriids 

 (Sesiids) is less highly specialised than it is found to be among 

 the Sphingids ; the specialisation does not differ materially in extent 

 from that of the other Microfrenatae, but it has proceeded further 

 in certain directions ; so, while the family is properly classed with 

 the Microfrenatae, it, at the same time, appears to represent an 

 offshoot of the branch which, later on, gave rise to the Sphingids. 

 There is, of course, he says, a possibility that the great similarity 

 of appearance and even of structure of an organ may arise from 

 similarity in environment and in the conditions of life, but in the case 

 of the ^Egeriids (Sesiids) and Sphingids the resemblances are more 

 than superficial, as marked in the microscopic as in the macroscopic 



