1 22 CREPUSCULA III A. 



form of the antennae, and other distinctive marks 

 already described in our introductory observations 

 It contains species of very dissimilar aspect and 

 economy, all of which, however, were included by 

 Linnaeus and his followers in the genus Sphinx. 

 Fabricius distributed them in three genera, Sphinx, 

 Sesia, and Zygsena ; names which have since been 

 employed to designate family groups. The indige- 

 nous species have recently been divided into four 

 families, which may easily be determined by the 

 following brief external characters: SPHINGID^, 

 with the palpi short, and the abdomen without a 

 terminal tuft ; SESIID.E, with the palpi short, and 

 the abdomen furnished with a tuft at the extremity ; 

 ^GERIID^E, with the palpi elongate, and the wings 

 most frequently hyaline ; ZYGJENID^E, having the 

 palpi likewise elongated, and the wings clothed 

 with scales*. The latter family contains only two 

 British genera, Ino and Anthrocera. The former 

 of these corresponds to the Fabrician genus Procris : 

 it has antennae very slightly curved, and thickening 

 gradually from the base nearly to the apex ; those 

 of the male with two rows of pectinations on the 

 inner side, but they are merely serrated in the 

 female; the apex without a tuft of hairs. The 

 palpi do not extend beyond the head, and are rather 

 thickly clothed with hairs. The species are not 

 numerous, and only one of them inhabits this 

 country ; it is named 



* Stephens' Illus. Haustettaia, i. p. 104. 



