1899.] AND SPIDERS PROM TROPICAL WEST AERICA. 867 



Measurements in millimetres. — Total length 14 ; length of cara- 

 pace 6-8, width 5-8 ; length of 1st leg 27-5, o£ 2ud 28, oi: 3rd 23-5, 

 of 4th 29. 



Loc. Benito Eiver (G. L. Bates). 



Eesembhng T. sjjinosissimus Karsch, from the same area, in 

 colouring, but recognizable, according to the description of the 

 latter, in having the legs ornamented with white transverse stripes 

 and spots. 



Although the type of this species is not quite adult, the 

 colouring will probably be found to afford a better criterion of its 

 specilic distinction than the form of the vulva. 



Thalassius leonensis, sp. n. (Plate LVII. fig. 21.) 



Colour a uniform reddish brown above and below ; carapace 

 and abdomen with a silvery white band extending from the sides 

 of the clypeus almost to the spinners, the band on the carapace 

 considerably narrower than the brown margin external to it. 



Carapace normally high, as high behind as in front, its width 

 equal to the area between the posterior border and the posterior 

 lateral eye ; its length equal to length of tibia or protarsus of 4th 

 leg ; slightly exceeding tibia of 1st and 2nd, width slightly exceeding 

 tibia of 3rd. 



Vulva practically as in T. spenceri Y. Cambr., from Cape Colony 

 (see P. Z. S. 1898, pi. iv. fig. 1 6), but longer as compared to its 

 width owing to the greater length of the lateral lobes. 



Measurements in millimetres. — Total length 21 ; length of cara- 

 pace 9-5, widtli 8 ; length of 1st leg 35, of 2nd 35-5, of 3rd 33, 

 of 4th 38 ; tibia of 4th 9-5, protarsus of 4th 9-8. 



Loc. Sierra Leone. 



The type of this species is the specimen from Sierra Leone 

 referred by Mr. P. Cambridge to T. spenceri, the type of which 

 came from East London in Cape Colony (P. Z. S. 1898, p. 30). 

 The two specimens appear to me, however, to be specifically 

 distinguishable. In T. spenceri the carapace is very slightly 

 shorter than tibia 1 (not longer as stated in the synopsis : loc. cit. 

 p. 29), and barely exceeds the 1st protarsus, and the width of the 

 carapace is a shade less than tibia 3 ; the lobes of the vulva, too, 

 are shorter and smaller. 



Thalassius batesi, sp. n. 



General characters as in T. leonensis, but with yellow band on 

 carapace and abdomen broader. Vulva differing in that the hairy 

 lateral lobes do not meet in the middle line, but are separated in 

 front by a median shming hairless sclerite, which is itself divided 

 by a central longitudinal sulcus. 



Measurements in millimetres. — Total length 22 ; length of cara- 

 pace 9-2, width 7-0 ; length of 1st leg 36, 3rd 32, 4th 39 ; 

 protarsus of 1st 8, of 4th 9"8. 



Loc. Benito Eiver ( G. L. Bates). 



Only the female known. 



