m THE BEITISH AND COPENHAGEN MUSEUMS. 219 



b*. Three hairs in flagellum ; generally ocular spots ; abdominal 

 tergites with not more than 6 hairs in front of the marginal 

 row. 

 a°. Hand at least I'l as long as the tibia; transverse grooves 

 generally wanting; obtuse or pointed hairs. 



Ill b. Subgroup of Ch. suhrobustus Balz. 

 6'. Hand less than 1"1 as long as the tibia; transverse grooves 



always present Ill c. Subgroup of Ch. bicolor Balz. 



6'. "Tactile" hair of tarsus IV. \ removed from base; tibia IV. with 

 dorsal median " tactile" hair ; tibia of the palps with two posterior 

 " tactile " hairs ; no sexual difference in galea ; hairs pointed 

 and almost simple Ill d. Subgroup of Ch. arcjentinus Thor. 



In the following are set forth a few remarks about the specific characters. The 

 structure of the eyes is, of course, of some importance, but undue value should not 

 be given to this character, as variations are sometimes found within the same species, 

 at least between males and females. The shape of the cephalothorax, or more 

 correctly the cephalothoracic shield (for instance, its length compared with its breadth), 

 the structure of the transverse grooves, of the granulations and hairs are, of course, of 

 some importance. The development of the galea is of no small value within certain 

 groups, but its sexual and often important individual variations must necessarily be 

 taken into account ; the flagellum is of more generic than of specific value. The shape 

 of the serrula and lamina interior shows specific differences, but as the individual 

 variations are often well pronounced, and as they are rather difficult to examine, I think 

 that they are generally not worth describing. 



In the description of the palps not only is the shape of the joints important, but also 

 the proportions between their length and breadth. The relative proportions of the 

 different joints are of the greatest importance. As far as the hand is concerned it 

 is necessary sharply to distinguish between the breadth and the depth, to give their 

 proportions to each other, and to compare them with the length of hand and finger. Not 

 only should the structure of the usual hairs be mentioned, but also the arrangement of 

 the longer and more slender " tactile " hairs. Valuable characters are often found in 

 the position of the tactile hairs as well as in the number and arrangement of accessory 

 teeth and " spots " or " sense-spots," in spite of often considerable variation within the 

 same species. 



The coxce, especially those of the fourth pair, often provide characters of great 

 interest and should always be examined, the sexual difference, of course, being taken 

 into consideration. In most previous descriptions the legs are scarcely mentioned, and 

 the workers on the systematics of this group have not at all realised the importance of 

 these appendages, not only in the definition of groups of species (cf. the structure of 

 the first pair of femora, of the claws and subterminal hair, and the position of the 



2h 2 



