28 Locomotory Limbs 



coxbe being movable in Sironini, but we can do so with resjject to the other divisions. In 

 Scorpiones the movability of the two first pairs of coxje is exjilained by their being furnished 

 with maxillary lobes; and the same consideration explains, as we have just mentioned, the 

 movability of the first coxae in Laniatores and Cyphophthalmi ; that the fourth coxse are 

 movable in Ricinulei is connected with the peculiar apparatus for hitching together cephalo- 

 thorax and abdomen, which will be described in a section dealing with these animals. 



In all Opiliones the movement between coxa and trochanter takes place in a perpendicular 

 plane, as also that between femur and patella and between tibia and metatarsus, whilst the 

 movement between trochanter and femur as well as between patella and tibia takes place in 

 a horizontal plane. In several Opiliones, amongst Laniatores as well as amongst Palpatores, 

 a small always immovable second trochanter joint is found at the base of femur, but this is 

 never found in C^'phopiithahni. Nor do these ever exhibit the division into spurious joints 

 which is seen, as regards femur in Nemastoina and Tomicomerus, and as regards tibia in 

 Tomicomerus, Mastobunus and Astrohunus (but not in Sclerosoma and " Homalenotus " depressus 

 Can.). 



In Cyphophthalmi the connection between metatarsus and tarsus admits of but very 

 little movement, a fact which constitutes a remarkable point of difference between that sub- 

 order and Laniatores as well as Palpatores ; as far as we have been able to ascertain, the 

 movement is perpendicular in Cyphophthalmi. In Laniatores (except Oncopodoidse) and in 

 Troguloidsi a shorter or longer portion of metatarsus, including its distal extremity, is developed 

 in a special manner; for instance in having a different covering of hair from that of the 

 other part of metatarsus. In Laniatores the distal portion of metatarsus, calcaneus (Sorensen), 

 is separated from the basal portion of metatarsus by a more or less slanting suture'; in 

 Troguloid^'- this is not the case, but calcaneus forms more (Trogulus) or less {Dicranolasma) 

 of an angle with the rest of metatarsus, for which reason it has generally been mistaken by 

 previous writers for the first joint of tarsus, a mistake which was so much the more natural 

 as calcaneus is without those processes which are found in the other part of metatarsus in 

 these animals. In Cyphophthalmi no calcaneus is, as a rule, developed, but in Parasiro cor- 

 sicus E. S. (PI. v., fig. 2 h) the distal third of the first and second metatarsus is separated 

 from the basal portion by a very slanting transverse groove ; both the basal portion of meta- 

 tarsus and tibia are densely studded with fine gi-anulations, while the distal portion and tarsus 

 are smooth. It may be mentioned as a peculiarity of Cyphophthalmi that metatarsus is 

 remarkably short ; in Parasiro it is only slightly, though unmistakably, shorter than tarsus 

 (PI. v., figs. 2 h and 2 i), but in all the other genera it equals in length only between 

 about one half and barely a third of tarsus. In Laniatores metatarsus is always longer 

 than tarsus; in Palpatoi-es with long legs it is much longer than tarsus; in those with short 

 legs of about the same length as the latter. 



Tarsi consist of only one joint in all Cyphophthalmi hitherto described, excepting only the 

 male of Purcellia illnstrans whose fourth tarsus (PI. IV., fig. 1 m) is divided into two joints 

 after the last exuviation. No great systematic importance can, however, be ascribed to this fact, 

 because in several species of Troguloidaj one or even all tarsi are undivided^, though Palpatores 



1 Sorensen's statement (e, p. .53) that the calcaneus is undivided in Cahttlwcralus n/Wi'am/s Luc. , and the same is 



movable in Trifenouychoidffi, is not correct. thecaseinanearly allied species in the Museum of Copenhagen, 



- With regard to the appearance of metatarsus in Trogu- and in Troyulus sinuosus \V. S. All tarsi are undivided in 



loidse we may refer to Hiirensen («, figs. 4 6, 6 6, 7). Trogulus albicerus W. S., which, however, is known only in 



' According to Simon {b, p. 301) the second tarsi are individuals not fully grown. 



