RATHBUN— MARINE BRACHYURA 207 



Coetivy ; 1 $ immature. 



C. 1. 28"6 mm., C. b. 377 mm. The chehpeds and the first leg on the right side 

 are represented only by thin soft appendages of small size. The specimen has a much 

 more Thalamita-like aspect than a larger $, 47 "6 x 6 3 '2 mm., taken at Aldabra by 

 Dr. W. L. Abbott. 



42. Charybdis hoplites (Wood-Mason). 



Charybdis (Goniohellenus) hoplites Alcock (4), p. 66. 



Saya de Malha, 47 fms., Sta. C 11 ; 1 $. C. 1. to tip of teeth, 27 "5 mm., 0. b. 

 43-6 mm. 



Not typical, because the posterior lateral spine is very little longer than the teeth 

 which precede it. The specimen is larger than that noted by Alcock. Compared with 

 a specimen still smaller, received from the Indian Museum, the angles of the posterior 

 margin are scarcely eared, though prominent ; the short ridges on the anterior gastric 

 region are single lines of granules. I am not able to say whether these are age variations, 

 or represent a subspecies. 



43. Charybdis, sp. 



Amirante, 25 fms., Sta. E 3 ; 1 $ juv., without chelipeds. C. 1. 4'8 mm., C. b. 

 6*5 mm., f. orb. b. 5*4 mm. 



Belongs to the " Gonioneptunus" division of the genus, in which the lobular external 

 process of the basal joint of the antenna is not in contact with the front. 



Front advanced, arcuate, 8-toothed, submedian pair of teeth a little wider than 

 median pair, two outer pairs subequal and a little smaller than median pair ; teeth 

 subtruncate. The two orbits together are nearly as wide as front. 



Postero-lateral corners rounded. 



Antero-lateral margin making a very slight angle with the axis of the crab ; 6 teeth 

 subequal, the 2nd and 5th slightly reduced ; 3rd to 6th inclusive sharp. 



Granular ridges of dorsal surface prominent and arranged as in C. subornata 

 (Ortmann)*, that is a ridge between the teeth of the last pair, three ridges in front of it, 

 the two foremost of which are broken in two, a ridge on the cardiac region, three short 

 ridges, one behind the other, on the branchial region. 



Merus of last foot more than twice as long as broad and armed with a strong spine ; 

 posterior margin of propodus spinulous. 



44. Thalamita crenata Latreille. 

 Thalamita crenata Alcock (4), p. 76. 

 Praslin, reef; 3 $. 



45. Thalamita dance Stimpson. 

 Thalamita dance (4), p. 77. 

 Egmont, reef; 1 $, I ?. 



* Zool. Jahrb. Syst., vii. 1893, p. 79, pi. 3, fig. 9. 

 SECOND SERIES— ZOOLOGY, VOL. XIV. 27 



