412 ME. H. M. BEENAED OK THE CHEEKETID^. 



position of the mouth, the ChernetidsB come midway between 

 Galeodes and Scorpio. The interesting homologies of these 

 mouth-parts I propose to discuss fully in a paper on the Graleo- 

 didse which is now in preparation. 



On the inner anterior edges of the basal joints of the pedipalps 

 there is a pair of movable lamellate processes (fig. 5), which, from 

 the strength of their muscles, clearly serve to hold prey in front 

 of the mouth, and perhaps to squeeze the juices out of soft 

 bodies. The homologous processes in nearly the same position 

 in Galeodes, Phrynus, and Thelypliomis are quite immovable, 

 and appear to be sensory. In the Mygalidse and Scorpionidse 

 they are still clearly traceable, but apparently much degenerated. 



The endosternite in the Chernetidae is especially interesting, 

 and affords additional evidence of the apodematous origin of this 

 structure, so patent in the Graleodidse. The endosternite in these 

 animals owes its origin to apodemes formerly present between 

 the leg-bearing segments which are now completely fused to- 

 gether. We accordingly find it situated far back in the cephalo- 

 thorax. It is now simply a small firm centre from which muscles 

 radiate to the four pairs of legs and to the genital operculum 

 (fig. 11). 



The Muscular System. 



The muscular system of Chernes is comparatively simple. It 

 is essentially of the same type as that of the Araneids. The 

 chief differences found in the musculature of Arachnids depend 

 upon the mobility of the coxae. In Galeodes, in which the coxae 

 are fixed, all the muscles which in the Araneids move these joints 

 are either wanting or are modified for other functions. In the 

 Chernetidae the coxae are movable, but not to the same exteut as 

 in the Araneids. "We consequently have a system of muscles 

 arising from the lateral and dorso-lateral regions of the cephalo- 

 thorax for the rotation and. raising of the coxae. As a rule, the 

 muscle which rotates and moves the coxa one way crosses that 

 which rotates it in the contrary direction. In addition to these 

 rotating muscles which, when acting together, must lift the 

 coxa, the muscles from the endosternite apparently also serve as 

 elevators. I could find no body-muscles attached to the tro- 

 chanter. All the leg-muscles proper are confined to the coxal 

 and other joints. 



The upper lip is provided with remarkable transverse muscles, 



