388 Mr. R. I. Pocock on new 



Measurements in millimetres. — Total length 100 ; length of 

 carapace 9, of tail 70 ; width of hand 4, of brachium 3, length 

 of movable digit 11 "5. 



Loc. Sirires, Talamanca {H. Pittier coll.). 



Centrums bicolor, sp. n. 



2 . — Colour of trunk a brownish black above ; sterna ochre- 

 yellow, mesiallj and marginally infuscate ; first four segments 

 of tail yellow above and at the sides, tinted with fuscous 

 below, the keels black ; fifth segment, vesicle, and lower 

 surface of fourth infuscate ; mandibles infuscate ; chelae 

 yellow, with the exception of a fuscous spot at the apex of 

 the brachium ; hands reddish black, with black keel, fingers 

 black with reddish tips ; legs entirely rich yellow, the 

 maxillary processes of chelse and anterior legs infuscate ; 

 pectines pale. 



Carapace sparsely granular as in ruhricauda. Tall almost 

 as in the latter, but tlie crests more numerously granular, 

 there being upwards of 25 granules on the infero-lateral 

 crest of the third segment ; sterna 2-4 coriaceous and punc- 

 tured, the fourth distinctly rugose and granular. Crests on 

 hand strong. 



Pectinal teeth 26-28. 



^ . — Like female in colour, and differing structurally in the 

 ordinary characters; sterna not granular. 



Pectinal teeth 28-29. 



Measurements in millimetres. — ? . Total length 109; length 

 of carapace 10, of tail 63. S- Total length 120; length of 

 carapace 11, of tail 82. 



Loc. ? . Poyo azul de Pirris (Atlantic) {T. Zeledon coll.). 

 ^. Santo Domingo de Golfo Dulce {H. Pittier). 



Centrums nigrimanus^ sp. n. 



^ . — Resembling C. Incolor in colour, but more closely 

 and coarsely granular above ; tlie fifth caudal segment 

 having its crests distinctly granular, and also the inferior and 

 lateral surfaces ; the vesicle on the other hand, instead of 

 being granular, is smooth below, and the tooth is much closer 

 to the aculeus ; the infero-lateral crests of the third caudal 

 segment are furnished with about 30 granules. 



Pectinal teeth 32-33. 



Loc. Oaxaca (type) (68. 74) : also a younger specimen of 

 apparently the same species from Honduras {Indo- Colonial 

 Exhibition). 



