Early Stages of Coleoptera. 331 



caused by the internal organs showing through. Mouth- 

 parts castaneous. 



Form short and thick, cylindrical, tapering at the ends. 

 Length, 9 mm. 



Head small, sides rounded. 



Prothorax broader than the head, margins crenated, sepa- 

 rated from the disk by an impressed line. Surface verj- con- 

 vex. 



Meso- and metathorax shorter and narrower than prothorax. 

 Abdomen broader than prothorax, the segments bulging con- 

 siderably, bristled at the sides beneath. The general shape 

 of the larva is shown by the tigure in which however the 

 head and thoracic rings are drawn a trifle too broad in pro- 

 portion to the abdomen — the result of attempting to correctly 

 represent a living and moving specimen. 



Legs in the form of an elongate cone, the joints regularly 

 decreasing in diameter from base to tip. There are no true 

 claws, but on three of the legs I can make out, with a three- 

 fourths objective, two diverging bristles near the tip of the 

 tarsal joint which may be the homologue of the claws. As 

 the possession of two claws has been looked upon as char- 

 acterizing the larvcc of x\dephaga, this is an important point. 



The larva shows to a remarkable degree, the profound 

 modifications which a change of habit may bring about. Be- 

 longing to a family the larvae of which are mostly active and 

 strong, living by rapine and murder, the larva of Brachinus 

 is a parasite on insects of its own order and is subject to 

 the many degradations of structure brought about by this 

 habit. Living in the cells or "cocoons" of Dineutes assimilis, 

 where it is perhaps brought as a very young larva clinging 

 to its host, it is without need of hard chitinous covering to 

 protect it from enemies or strong limbs to bear it in search of 

 prey. Its covering is consequently soft and yielding, resem- 

 bling rather that of a Hymenopterous larva than a Carabid, the 

 legs become mere props and seem not to be used in drawing 

 the body along when the insect makes the little progress of 



