156 



PHYSIOLOGY OF INSECTS. 



joints takes place without any marked indentation or 

 protuberance : filiform or JiUformes (fig. 2), when stouter 

 and shorter, and preserving through- 

 out a uniform substance : incrassa- 

 ted or accrescentes (fig. 3), when 

 resembling the last, excepting that 

 they gradually increase in substance 

 towards the apex : fi.isiform oxfiisi- 

 formes (fig. 4), when stoutest at the 

 middle and tapering very gradually 

 to each end : moniliform or monili- 

 formes (fig. 5), differing fi"om the 

 filiform in one character onlyj 

 each separate joint is oval or glo- 

 bose, and the portion connecting it 

 with the next joint is very slender ; 

 the joints thus resembhng beads on 

 a string : serrated or serrat<B (fig. 6), 

 having each joint produced on one 

 side at the apex, so that together 

 they resemble the teeth of a saw : 

 pectinate or pectmiformes (fig. 7), 

 in which the joints are still more 

 produced, or rather, are ftimished 

 on one side with slender process- 

 es, resembling, in some degree, the teeth of a comb: 

 flabellate ox Jlahelliformes (fig. 8), having the processes 

 of the joints still longer, very thin, and, when at rest, 

 lying flat on each other, like the folds of a fan ; the an- 

 tennae of some insects are flabellate throughout, others 

 have only the apical portion flabellate : in the latter case 

 they are termed lamellate or lamellaice (fig. 9) ; this form 

 is not uncommon, the whole of the Linnean genus Sca- 

 rah(BUS, possessing tliis structure, and thence being now 



