PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 507 



which is short, not reachiug beyond the peduncle of the antenuula, 

 acutely triangular in a side view, considerably upturned, and wholly 

 unarmed. 



As in Acanthephyra Af/assizii, the eye-stalks are short and terminated 

 by small hemispherical black eyes, which face slightly inward when the 

 stalks are directed forward. 



The antennulse, too, are very nearly as in Acanthephyra Agassizii, except 

 that the proximal portion of the outer fiagellum is much less expanded, 

 though very much stouter than the inner. The antenna! scales are im- 

 perfect at the tips, but are less rapidly narrowed distally, and are ap- 

 parently more nearly as in Acanthephyra microphthalma. 



The mandibles are essentially as in Acanthephyra Atjassizii, but are 

 very nearly alike on the two sides, the posterior part of the mesial edge 

 of the ventral process in each being armed with six or seven acutely 

 triangular teeth, in front of which the margin is sharp and chiteuous, 

 but not serrated, though there is a small tooth at the anterior end of 

 this uuserrated edge in the right mandible and a sharp angle at the 

 same point in the left. The first maxilhe are very like those of Acan- 

 thephyra Agassizii. The anterior division of the distal segment of the 

 protognath of the second maxilla is much expanded at the mesial edge, 

 where it projects farther forward and is more than twice as broad as 

 the posterior division ; the endognath is more slender ; the anterior lobe 

 of the scaphognath is a little narrower and more evenly rounded at the 

 end. The maxillii)eds do not difi'er from those of A. Agassizii, except 

 that the antero-mesial angle of the exopod is a little more obtusely 

 rounded, nor the first gnathopods, except the distal part of the endopod, 

 which is more nearly as in Acanthephyra gracilis, the dactjdus being 

 longer than broad and terminally attached to the propodus by a slightly 

 oblique articulation. The second gnathopods are imperfect at the tips, 

 but are evidently very nearly as in Acanthephyra Agassizii, and appar- 

 ently reach to about the tips of the antennal scales. 



The first peraiopods are about as long as the carapax including the 

 rostrum, and are clothed with numerous hairs ; the ischium and raerus 

 make about half the length of the endopod, and are strongly compressed 

 and broad, the merus being considerably more than a third as broad as 

 long ; the carpus is about three-fifths as long and half as broad as the 

 merus ; the chela is somewhat stouter than the carpus, not far from 

 twice as long, and tapered distally to the bases of the digits, which are 

 about a third of the whole length, verj^ slender and strongly curved at 

 the tips. The fifth peneopods are about a fourth longer than the first 

 and are clothed with very few hairs ; the ischium and merus make fully 

 half the entire length ; both are broad and strongly comi)ressed, and the 

 latter is fully a third as broad as long, with the dorsal margin nearly 

 straight and the ventral strongly curved upward to the articulation 

 with the carpus, which is very slender and scarcely longer than the 

 breadth of the merus ; the propodus is about twice as long as the car- 

 pus and no stouter; the dactylus, exclusive of the terminal spines and 



