30 Locomotor}/ Limbs. Mouth 



Thor. (PI. I., fig. I p); at the same time the difference between the hairy covering of 

 that part of the under surface on which the animal treads and the rest of it is quite as 

 marked as in the species mentioned before. In Purcellia (PI. IV., fig. 1 I) the arrangement is 

 dilferent ; the apical portion of the first tarsus is somewhat thicker than the other part, and 

 the hair on the under surface of it closer and finer than on the rest of the under surface and 

 on the other tarsi; but the area covered by these hairs, which here have a slanting position, 

 is not sharply defined, as they are found some distance up the proximal part of the joint. In 

 Siro and Parasiro (PI. V., figs. 1 k and 2 h) no difference in the hair}' covering of tarsi is 

 observable, and we may therefore probably conclude that these animals tread on the ends of 

 all their tarsi. 



In Cyphophthalmi all the legs are furnished with one large and very movable claw. In 

 Ogovia the claws on all the legs are of equal size, but in the other genera they increase 

 in size from the first to the fourth pair, the largest increase occurring between the 

 second and third pairs. In all Palpatores hithei'to described all the legs carry one claw; 

 in Laniatores the two first pairs of legs have one claw, whilst the two posterior pairs have 

 two, excepting the family Triisenonychoidse, where the two posterior pairs of legs have only 

 one claw, which however differs in shape from those on the two anterior pairs. The majority 

 of Sironoidse have simple claws : but in Parasiro corsicus (PI. V., figs. 2 k and 2 I), and 

 a North American species, of which Professor Thorell has kindly lent us some drawings made 

 by the late Dr. Marx, the claws are all serrated on the under side. Amongst Palpatores 

 no instance of serrate claws on the legs has hitherto been described', but amongst Laniatores 

 in many genera the two posterior pairs of legs frequently have pectinate claws ; the two 

 anterior pairs never carry such. 



5. llie MoiUh and Stomotheca. 



It is well known that in Cyphophthalmi the mouth is placed in a cup-shaped depression 

 to which Thorell gave the name of stomotheca (c, p. 23), which we adopt. The stomotheca 

 is formed (PI. I., fig. 1 I) by the first pair of coxse, but is closed behind by the maxillary 

 lobes of the coxae of the second pair of legs. The inner surface of the first pair of coxse 

 forms always the side walls, and in some genera, viz. Pettalus, Purcellia, Siro and Parasiro, 

 these surfaces also partly close it above. It is not, however, the entire inner (or anterior) 

 surface of the first pair of coxse that enters into the composition of stomotheca, but only 

 the proximal portion, which as a rule is the longer one, whilst the distal portion (between 

 e and / in fig. 1 I) .slants inwards and forwards, forming a more or less sharp corner (/) 

 with the proximal part. The under surface of the coxa makes an angle with the proximal 

 portion of the inner surface, which forms the wall of stomotheca, but rounds off more 

 gradually into the distal portion of the same, which is situated in front of stomotheca. 

 On the under surface of the first coxa a ridge^ runs along the border of stomotheca, our 



1 We express ourselves thus cautiously, because the matter - It is no doubt to this ridge, not to the real maxillary 



does not appear to us to have received much attention. It is lobe, that Simon refers when he says (h, p. 142), '• Lobe 



well known that the claws of palpi are serrate in several maxillaire de la premiere paire reduit a un simple rebord 



Phalangioidse, such as Sclerosoma and allied genera, Leio- sonde, immobile," because in speaking of the first pair of 



bunum, several species of Gyas, and, according to Thorell, in coxse he says {a, 241) that they are " car^n^es du coti interne 



the majority of his group GagreUini. et doivent jouer la role de m^choires." 



