ZOOLOaY AND BOTANY, MICROSCOPY, ETC. 207 



assumes a spider-like attitude for the purpose of alarming its enemies. 

 He discusses the matter at some length, and finds that " the larva of 

 Stauropus fagi bristles with defensive structures and methods. When at 

 rest it is concealed by a combination of the most beautiful protective 

 I'esemblances to the commonest objects which are characteristic of its 

 food-plant. Attacked, it defends itself by a terrifying posture, which is 

 made up of many distinct and highly elaborate features, all contributing 

 to this one end. Further attacked by an insect-enemy it reveals marks 

 which suggest that it is of no interest to its enemy, for another parasite is 

 already in possession. 



The black colour of the eggs of Paniscus cephalotes appears to serve 

 as a warning to the other insect parasites belonging to the same and other 

 species that the larva of Cerura vinula is already occupied. The 

 defensive value of " tussocks " and the associated black intersegmental 

 markings are next considered. A " tussock " may be defined as a tuft 

 of fine hairs, very closely placed, and of approximately equal length, so 

 that the structure is flat-topped ; the constituent hairs bristle with 

 minute lateral branches ; if seized the fine hairs come out in immense 

 numbers in the mouth of the enemy, and produce such an effect that the 

 larva escapes unhurt. When the larva is irritated the tussocks are held in 

 an especially conspicuous manner, while the black markings are revealed, 

 and assist by rendering the tussocks more obvious and giving an appear- 

 ance of increased projection. 



The larvae of the Cochliopodidae gain protection by assuming a form 

 which is quite unlike that of a caterpillar, and does not suggest the 

 appearance of the food of any insect-eating vertebrate. Other points on 

 which, in this interesting paper, Mr. Poulton has notes are the protective 

 resemblances of the larvae of Geometra papilionaria, a proof of the pro- 

 tective value of dimorphism in larvae, the protective resemblance of the 

 pupa of Apatura iris, the defensive secretion of the larva of Croesus varus, 

 the geometriform structure and attitudes of Euclidia mi, and the 

 determination of sex in certain living lepidopterous larvae. As to the 

 last point, use has been made of the distinctness of the testes which lie 

 beneath the skin of the fifth abdominal segment, and which can be easily 

 seen beneath the skin of all fairly transparent larv^, and by careful 

 examination in moderately transparent forms. 



New Genus of Pyralidse.* — Lord Walsingham describes a remark- 

 able Indian Pyralid, which he calls Coenodomus hockingii. The larvae 

 are gregarious, and live in strong tubes of white silk, of the consistency 

 of stout cardboard ; these are open at both ends, and from three to 

 fifteen are agglomerated together, the heads of the larvae projecting from 

 one or other end, according to the position of the leaves of their food, to 

 which the whole mass of tubes is attached by stout silken threads con- 

 sisting of many strands. The walls of these tubes are double, and of 

 very curious construction ; the inner lining of white silk is smooth and 

 rather shining, while the outer layer is much stouter and has an uneven 

 surface ; this last is due to the interposition of larval excrement 

 between the two walls. A more perfect arrangement for keeping off 

 heat from the body of the larvae cannot be imagined. The silk at the 

 ends of the tube is frayed out, and has apparently been used for attaching 

 them to the leaves and twigs, or for changing the position of the 



* Trans. Linn. Soc. Lond., v. (1888) pp. ■17-52 (1 pi.). 



