vi BUTTERFLIES SKIPPERS 363 



it is said to connect Papilionidae to some extent with Hesperiidae. 

 The larvae of this family are remarkable on account of a curious 

 process on the thoracic segment called an " osmeterium." It is 

 usually retracted, but at the will of the caterpillar can be everted 

 in the form of a long furcate or Y-shaped process ; there is a 

 gland in the osmeterium, and as a result a strong odour is 

 emitted when the exstulpation occurs. 



The pupation of Papilionidae is similar to that of Pieridae, 

 the pupa being placed with the head upwards, fixed by the tail, 

 and girt round the middle. A very curious diversity of pupation 

 occurs in the genus Thais, in which the pupa is attached by the 

 tail as usual, and which is quite exceptional also by a thread 

 placed at the top of the head. Scudder thinks there is also a 

 girdle round the middle, but Dr. Chapman inclines to the view 

 that the thread attaching the head is really the median girdle 

 slipped upwards. The pupation of Parnassius is exceptional, 

 inasmuch as, like Satyrides, it is terrestrial, in a slight construc- 

 tion of silk. 



Fam. 6. Hesperiidae (Skippers). -Six perfect legs: metanotum 

 not free, largely covered Toy the mesonotum. A pad on the front tibia. 

 Claws short and thick ; empodium present. Although this family 

 has been comparatively neglected by entomologists, upwards of 

 2000 species and more than 200 genera are known, and it is not 

 improbable that it may prove to be as extensive as JSTymphalidae. 

 We have already said that Hesperiidae is generally admitted to 

 be the most distinct of the butterfly groups. It has been thought 

 by some taxonomists to be allied to Papilionidae, but this is a 

 mistake. It is undoubtedly more nearly allied to Heterocera, 

 and when the classification of Lepidoptera is more advanced, so 

 that the various natural groups placed in that sub-Order are 

 satisfactorily distinguished, it is probable that Hesperiidae will 

 be altogether separated from Rhopalocera. We have already 

 mentioned that E. Reuter considers the Hesperiidae to be phylo- 

 genetically unconnected with Rhopalocera proper; but though 

 quite ready to admit that he will probably prove correct in this, 

 w T e think Lepidopterists will not be willing to recognise the 

 family as a sub-Order equivalent in value to all Heterocera. 



The body is shorter and thicker than it is in most butterflies, 

 and is pointed at the tip rather than knobbed or bent down- 

 wards; the wings are less ample; the antennae are not truly 



