248 STATES OF INSECTS. (Pupa.) 
nal segments, also, are fringed with spines*. The ab- 
domen of the pupa of Ctenophora pectinicornis is armed 
with several strong conical spines, pointing mostly to- 
wards the tail, which is likewise the case with that of 
Tipula lunata®. As the above pupe are usually subter- 
ranean or subcortical, the spines assist in pushing them 
out of the ground, &c. ‘The respiratory horns that 
proceed from the thorax of the pupz of many of the 
aquatic gnats will be noticed in another place. ‘Those 
of Corethra culiciformis and of some other aquatic gnat- 
like Diptera, have their anus furnished with a pair of 
oars, or natatory laminze, by which they rise to the sur- 
face‘. 
The figure of obtected pupz, or chrysalises, is more 
uniform. ‘They are commonly obtuse at the anterior 
extremity, and gradually contracted to a point at the 
posterior, or tail. The outline usually inclines to a long 
oval or an ellipse; but in some, as Attacus Jo and Artemis 
Luna, the pupa is shorter and more spherical. In Ura- 
pteryx sambucaria it represents an elongated cone, and in 
Hepiolus it is nearly cylindrical. In the butterfly tribe 
the outline is frequently rendered angular by various 
protuberances. 
In all these pupze may be distinguished the following 
parts :—jirst, the Head-case (Cephalo-theca), or anterior 
extremity ; secondly, the Trunk-case (Cyto-theca), or in- 
termediate part; and thirdly, the Abdomen-case (Gastro- 
theca). 
* De Geer vi. 237. t. xiv. f. 8. 
> Reaum. v. ¢. ii. f. 7. The anal and ventral spines of Tipula re= 
plicata are also remarkable. De Geer vi. ¢. xx. f. 14. 
© De Geer Ibid. 377. t. xxiii. f. 8, 9. n. Reaum. v. 42. t. vi. f. 9. mm 
