INTRODUCTION. ' 21 



Secondly : a larva of a cylindrical form, generally swelled or thickened at the 

 fourth or fifth section of the body, attenuated towards the head and posterior extremity; 

 in the typical genera naked or covered with short, obtuse, fleshy protuberances ; 

 in the extreme genera, at the boundary of the neighbouring groups, covered 

 with a close silky down or with short scattered hair, most remarkably distinguished 

 by a furcula or forked tentaculum, situated between the head and neck, which may 

 be drawn back or thrust forward at pleasure. Pupa angulated and mostly tuber- 

 culated ; in the typical genera, and in those at the confines of the first group, 

 attached by the posterior extremity, braced, and vertically suspended with the head 

 upwards ; in the genera approaching the third stii-ps perpendicularly suspended, 

 according to the habits of that stirps. The caterpillar of this division is distin- 

 guished in the diagram as the Chilognathiform or Juliform type. 



Examples: Plate iii, fig. 14, 15, 16, 17, 18, 19, 20. Plate iv, fig. 6, 7, 8, 9, 10, 

 11, 12, 13. By an oversight the pupa, both in this and in the former stirps, has 

 been placed in a vertical attitude, which the reader is requested to bear in mind ; 

 the natural attitude is exemplified in plate iii, fig. 1, a. 2, a. 3, a. 4, a. and 5, a. ; 

 but in some instances the head is downwards ; these will be pointed out in the 

 descriptions. 



Thirdly : a cylindrical larva, strikingly characterized by its terrific or threatening 

 aspect, being covered with sharp, rigid, erect processes, often of great length, but 

 diversified in the different subdivisions, arranged in regular longitudinal lines along 

 the body of the larva, and beset with numerous diverging spines disposed in a verti- 

 cillate manner. It is distinguished by the designation of CJdlopodiform or Scolopen- 

 driform larva. The attitude of the pupa is the reverse of that of the typical forms 

 in the two former divisions : it is attached by the abdomen, while the head is 

 directed perpendicularly downwards : in form it is greatly diversified. 



Three examples only of this form are given with a view to show its general habit, 

 in plate iii, fig. 21, 22, and 23 ; the remaining modifications, which are numerous, 

 will follow connectedly on succeeding plates. 



Fourthly : a lengthened cylindrical striated larva, somewhat smaller at each end, 

 apparently of an agile habit, naked, or covered with a slight down, having a head of 

 moderate size, armed with two erect spines, or provided with a moveable shield, 

 often of great size and beset with erect hornlike processes : but the chief charac- 

 teristic of this division consists in two very strongly marked lengthened filiform or 

 spinous appendages from the abdomen. The pupa is attached by the tail and sus- 

 pended perpendicularly as in the last division; it is in general terminated by two 

 points, of various form and length. The illustration of this division will be given with 

 that of the former in the course of the work. One specimen only is figured on the 



diagram, 



