172 STATES OF INSECTS. 



considered as organs of respiration, and their taper forks, 

 are moulded upon the plan of the Stomapodiform Crus- 

 tacea, and the long seta which terminates the abdomen is 

 upon the Thysanuriform plan a . 



Trichoptera. The larvae of this order appear also to 

 be constructed upon a double plan. The respiratory 

 threads observable in both the upper and under sides of 

 the abdomen connect it with the Stomapoda, and its cy- 

 lindrical elongate body with Chilognathiform types in the 

 Lepidoptera b . 



Lepidoptera. The great majority of larvae in this or- 

 der are Chilognathiform, but there are exceptions to this 

 remark. Those of the Geometrce recede from this type, 

 both in their motions and the distance and number of 

 their legs. In both these respects they represent the Lce- 

 modipoda in the Crustacea c . Other caterpillars are Onis- 

 ciform ,■ and a third sort seem to leave the Annulose type, 

 and imitate that of the Mollusca, and one is figured by 

 Madame Merian d which appears to tend even to the 

 Chilopodiform type. 



Hymenoptera. In this order the larvae of the saw-flies, 

 Tenthrcdo L., are in general Chilognathiform, though some 

 are Onisciform, others Limaciform, and those of Lyda F. 

 [Cephaleia Jur.) and Sir ex e have a Vermiform tendency, 



a De Geer ii. t. xxiii. /. 9 — 14. Comp. Reaum. iv. t. xv. 

 /• 1, 2. 



b De Geer ii. t. xiv./. 7. &c. The caterpillar of P. G. Scratiotata 

 L. like those of Phryganece, has these respiratory threads. Ibid. i. 

 t. xxxvii./. 2 — 6. De Geer has described the larva of a Phryganea L. 

 which is without any respiratory threads, ii. 569. t. xv./. 10. 



c Hor. Entomolog. 401. Montagu in Linn. Trans, vii. 67. 



d Ins. Surinam, t. xxviii. Compare Ibid. t. xix. right-hand figure. 



* Plate XVIII. Fig. 10. 



