( cxiv ) 



varies very much. In this case, at least, one would expect 

 there must be some object in this comb ; but so fai-, I have 

 been unable to find any evidence that it has any special 

 advantage over the simple claw — closely allied species with 

 apparently the same habits having them simple and pec- 

 tinate. One curious thing connected with this form of claw 

 is that it appears suddenly, as it were, in the midst of species 

 which have simple claws, and the species with simple and 

 pectinate claws closely resemble each other in appearance. 

 Ophion, for example, has pectinate claws, but Paniscus, which 

 so closely resembles it, and all the allied Ichneumonidse have 

 them simple. 



Again, in the Ohrysididse, Hovialus auratus has pectinate 

 claws, but Holopyga, which is allied to it, has only a slight 

 tooth. In the Carabidee, Dendrocellus, a graceful green insect, 

 with narrow thorax and more or less yellow legs, has pectinate 

 claws, but the next genus Dryjita, which might be mistaken 

 for it, has them simple. In another grouj^ of Carabida3, 

 Ortliogonius, a flat, broad, oblong, brown insect has pectinate 

 claws, but A2)sectra, which closely resembles it, has them simple. 



In the Elateridse Adrastus pollens has pectinate claws, and 

 Agriotes 2^(^ttidulus, which might be mistaken for it, and 

 indeed was mistaken for it by old authors, has them simple. 

 All these stand out more or less isolated. The only case 

 known to me where there is anything like a passage from the 

 simple to the pectinate form occurs in the Carabidse allied 

 to Dromius. Some species have them simple, Lionychus 

 quadrillum for example. Some have them slightly pectinate, 

 that is to say, with very short teeth, not much more than 

 serration, others have them strongly pectinate. Demetrias 

 atricapillus has them pectinate, Aetophoms has them simple. 

 Again, many species of Lebia and its allies have pectinate 

 claws, whilst others have them simple. In the Lamellicorns, 

 Listronyx has them pectinate. 



In the Dascillidte, Odontonyx and Faraliclias have the claws 

 beautifully pectinate, and they are so in the Elaterid^e of the 

 extensive genus Melanotus and in Aptopus. All the Hetero- 

 mera of the family Cistelidse, have the claws pectinate. This 

 is the only case known to me where all the members of a 



