ZOOLOGY OF FERNANDO NORONHA. 



519 



border, without accessory teeth ; its greatest length equal to one 

 half of the length of the superior margin of the manus. Anterior 

 margin of the "thumb " on the inner side nearly vertical, forming 

 an obtuse angle with the inclined superior margin. Superior 

 and inferior margins of thumbs on the outer side nearly parallel •. 

 in front united by a distinct anterior border, which below 

 curving forwards forms with the inferior border the tooth of the 

 thumb, which does not project so far forwards as the anterior 

 margin of the dactylus. 



Upper margin of the manus with a very faint constriction in 

 its anterior half; right and left sides smooth, without depressions ; 

 lower margin with a very faint depression in its anterior half; 

 upper margin marked with sulcus, which in the middle of the 

 hand curving downw^ards and backwards runs to the carpal joint. 

 Carpus rounded above, not bearing a tooth ; meros three-sided, 

 flattened below, not bearing a tooth above in front. Smaller 

 manus simple, without constrictions or depressions ; dactylus, 

 thumb, and upper margin of manus approximately equal in 

 length ; carpus furnished with a blunt tooth above, equal in 

 size to the carpus of the larger manus ; meros resembling the 

 meros of the larger manus. 



In the second pair of legs the first carpal segment is as long 

 as the second and the third together ; third about half the length 

 of the second, equal in length to the fourth, shorter than the fifth, 

 which itself is shorter than the second. 



Meros and carpus of third and fourth pairs of legs not spined. 



In size and form resembling A. Uchvardsii, but difi^ering from it 

 in having the larger hand very lightly constricted above and below. 

 Moreover, there is a large black spine on each side of the telson. 



Alpheus panamensis, Kingsley. 



1878. Alpheus panamensis, Kingsley, Bull. U.S. Geol. Surv. iv. p. 192. 



Carapace smooth, furnished in front with a strong rostrum, 

 which projects considerably beyond the sx)ines of the orbital 

 hoods, almost as far as the second segment of the antennular 

 peduncle ; separated by a depression from the ocular hoods, each 

 of which is furnished with a small sharp spine. 



Lower margin of hood continuous below the spine. 



Antennular spine reacliing slightly beyond the margin of the 

 basal segment of tlie peduncle. Second segment of peduncle 

 longer tb.an the third, as long as the first. 



