ZOOLOGY OF FERNANDO NORONKA. 



509 



The arrangement of tubercles and teeth upon the second, third, 

 and fourth pairs of legs is nearly the same as the arrangement 

 upon the first pair, but the posterior row of meral tubercles 

 becomes progressively fainter from before backwards, and the 

 teeth of the anterior row become gradually modified in form and 

 number until, in the posterior pair of limbs, this row is formed 

 of four teeth, two larger and two smaller, the larger and smaller 

 alternating, and one of the larger being the most proximal of the 

 series. Width of carapace 7j mm., length 7 mm. 



One male specimen was obtained. 



To guide me in the identification of the "Fernaudo-Noronha 

 specimen, which I refer to T. cristuUpes (Stimps.), I have had to 

 trust to the descriptions and figures of that species published by 

 Dr. Stimpson and by M. Alphonse Milne-Edwards, and to my own 

 examination of a single imperfect individual which was taken off" 

 Cape St. Lucas (California), and presented to the British Museum 

 by the Smithsonian Institute. 



Now, although with the above-mentioned figures and descrip- 

 tions the specimen from Eernando Noronha does not present 

 agreement in all points, yet, making allowance for possible errors 

 on the part of the artists, I should unhesitatingly have referred 

 this specimen to T. cristuUpes (Stmps.) were it not for the fact 

 that the points of diff"erence between it and the specimen from 

 Cape St. Lucas are by no means inconsiderable. 



In the Californian specimen the sulci defining the regions of 

 the carapace are conspicuously deeper, and the tubercles of the 

 same part, though exhibiting in the main the same arraogement, 

 are much larger. This is especially the case with regard to those 

 of the branchial region, the three low tubercles of the antero- 

 lateral margin in the Noronha specimen being represented 

 in the Californian specimen by three large upstanding teeth. 

 Again, with regard to the limbs, the merus of the chelipede in 

 the Californian specimen is furnished below in front with one 

 large compressed tooth and the pollex is armed with two 

 small teeth, these small teeth being scarcely represented in the 

 Noronha specimen. The other limbs present much the same 

 arrangement of teeth in the two specimens, but, as in the case of 

 the carapace, the teeth of the Californian specimen are relatively 

 larger than those of the Noronha specimen. 



I am well aware that the differences thus set forth are ampiy 

 sufficient to justify the separation as distinct species of the spe- 



