420 ON SOME RARE ARACHNIDS 



resembles that spider, from which, however, it differs in being 

 of a generally redder colour, especially as to the scuta. 



The EYES are arranged much as in O. pulcher (Tempi.). 

 That is to say, the posterior row consists of four large oval 

 eyes, of which the centrals are slightly larger than the laterals. 

 All four are in contact, and the row is curved, the slight con- 

 vexity being in front. The two anterior eyes are separated 

 by a space equal to the diameter of one of them. In /. velox, 

 on the contrary, they are in contact, and the six eyes surround 

 completely a small portion of the caput. 



The LEGS show a very curious dissimilarity in the patellae of 

 the several pairs. These decrease in length from before 

 backwards. The first patellae are very long, nearly equalling 

 the first tibiae in this respect. The fourth patellae are the 

 shortest. In /. velox on the other hand the patellae are all 

 short and approximately equal. The patellae and tibiae of the 

 first two pairs of legs each bear beneath a double row of dis- 

 tinct but not very long spines. There are three pairs of these 

 on each patella and five pairs on each tibia. These are absent 

 on the third and fourth pairs of legs. The metatarsi bear beneath 

 some rather long hairs but no spines. The spines borne on the 

 patellae and tibiae of the first two pairs of legs are erect or 

 nearly so ; they are much weaker than the spines borne on the 

 tibiae and metatarsi of the first two pairs of legs in /. velox. 

 These last are recumbent and lie along the long axis of their 

 respective joints. In both species, however, the spines are 

 probably capable of a considerable amount of movement at 

 their socket-like bases. 



The ABDOMINAL SCUTA are very characteristic. The dorsal 

 SCUTUM is of a long oval form. It begins near the anterior 

 end of the abdomen, and covers about two-thirds oi'iis length. 

 It is, however, very narrow, and leaves on each side a wide 

 area uncovered. It is of a reddish brown hue. In /. velox 

 the colour is paler, and the scutum only reaches halfway doivn 

 the abdomen. 



The EPIGASTRIC SCUTUM covers the epigastric region, and 

 the pulmonary sacs ; it embraces the abdominal pedicle and 



