448 R. I. Pocock — On Eophrynus and Allied Arachnida. 



these segments. Hence the first free sternal plate corresponds to 

 the second tergal. The sternal plates are practically smooth but 

 for the presence of a pair of tubercles on each side of those lying 

 between and including the fourth and eighth. The innermost of 

 these tubercles on each sternite are widely separated from the 

 middle line. Beyond the external tubercles on the fourth, fifth, 

 and sixth sterna there is on each side a conspicuous upstanding 

 ridge, representing perhaps the lateral margins of the plates. 

 Beyond this crest the lateral area of the somite slopes upwards to 

 the margin of the lateral tergal lamina. It is noticeable that the 

 posterior border of the fourth, fifth, sixth, and seventh is elevated, 

 as is the case with the sterna in many Opiliones. 



The posterior border of the third sternum is sharply defined, 

 forming a pair of slightly arcuate crests stretching each from near 

 the middle line to the lateral border. The median portion of this plate 

 also presents a distinct and wide pit-like depression which evidently 

 underlies and apparently has a direct connection, possibly in the 

 way of muscular attachments, with the tubercular elevation on 

 the third tergal plate. Since the lateral portions of the posterior 

 border of the third sternum are more decidedly elevated and arcuate 

 than those of the preceding or succeeding sterna, it is possible that 

 the slit on each side they overlie represents the stigma of a respiratory 

 organ. I can find no other structure on the sternal surface of any 

 of the somites that suggests the stigma either of a tracheal tube 

 or a pulmonary sac. 



In front of the sternum of the third somite two sterna are, 

 I think, traceable. The anterior of these, which probably belongs 

 to the genital somite, is triangular in form, and projects forwards 

 between the coxae of the appendages of the last pair. Its 

 posterior border is somewhat irregular, but shows a distinct though 

 small median emargination. The second sternum is narrow. Its 

 posterior border is sharply defined in the middle line, and exhibits 

 a pair of lobate sclerites exactly similar in size and position to those 

 on the second sternal plate of some of the Amblypygous Pedipalpi. 

 There seem to be no reasons for thinking that the genital orifice 

 was situated in front of the first sternal plate as it is in the 

 Opiliones. Presumably it opened behind it as in the Pseudoscorpiones, 

 Pedipalpi, etc. 



The type of Eophrynus prestvicii gives the following measurements 

 in millimetres : — Total length, 27; length of carapace, 8 ; its posterior 

 width, 9 ; length of its median elevated area, 7 ; posterior width of 

 latter, 4-5; length of opisthosoma, 19; its greatest width (approx.), 

 17 ; length of its sternal area from anterior end of first sternite to 

 posterior end of anal tubercle, 16 ; length of coxa of fourth leg 5 '5, 

 trochanter 4, femur 9-5, patella 5 ; of same segments of third 

 leg, 4-5, 3, 6, 3. 



{To be continued in our next Number.) 



