OF THE COASTS OF SOUTH AMERICA. 57 
obtusely carinated along the centre; each of them delicately ciliated at its anterior 
margin. 
Feet of moderate length: the anterior pair (in the female) considerably smaller than 
the rest, slender, slightly compressed, and smooth; hand with a small obtuse tooth 
above and one beneath, at the base; the fingers with the margins minutely serrated. 
The moveable finger longer than the other, and curved over its extremity. The re- 
maining pairs of feet decreasing in length from the second to the fifth, depressed, and 
slightly hairy ; the antepenultimate joint has a shallow sulcus on each side; the ter- 
minal joint is minutely toothed beneath. 
Of the colour nothing can be said, as both the specimens preserved by Mr. Cuming 
were bleached. 
Length 9 lines ; breadth 8 lines. 
Found by Mr. Cuming at the Gallapagos Islands in sandy mud, at the depth of six 
fathoms. 
OrTHONIA QUINQUE-DENTATA. 
Tab. XII. Fig. 2. 
Oth. teste margine laterali dentibus quinque triangularibus acutis armato. 
Pitho quinquedentata, Bell, in Proc. Zool. Soc., part iit. p. 172. 
Hab. cum precedente, ad Insulas Gallapagos dictas. 
2 Mus. Soc. Zool., Bell. 
This species resembles the former one in most of its characters. It differs, however, 
in the number of teeth on the lateral margin, and very considerably in size. The frontal 
portion of the carapax is more produced, and the surface more scantily granulated, 
and without spines. The two specimens of the former species are nearly an inch long, 
and are both evidently immature, as the abdomen is but very little developed. Those 
of the present species, which are very little more than half an inch in length, have the 
abdomen fully developed, being very prominent, and of a circular form. 
The general colour is brown; the feet with alternate rings of reddish and brown. 
Two female specimens were found by Mr. Cuming with the former. 
‘Ye Genus Tycue. 
Testa oblonga, depressa, angulata, anticé declivis, fronte lato, rostro bidentato piloso 
terminata ; rostri dentes compressi, obtusi, apicem versus interné emarginati. 
Orbita supra latissima, in dente prominenti complanato anticé producta, infra carens. 
Oculi pedunculo elongato minores. 
Antenne interiores in fossula ad basin rostri inserte. 
Antenne exteriores rostro longiores, articulo basilari latiusculo, anticé angustiore ; arti- 
culo tertio secundo abrupté minore ; omnibus externé pilosis. 
VOL, Il. I 
