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rh'oci'VDINGS OF THE NATIONAL MUSEUM. 



VOL. XXXV. 



curved backward and more strongly produced at the distal end. 

 From O. gra rilandica (Hensen) it differs in the same features as well 

 as in having the infero-lateral angles of the third abdominal seg- 

 ment rounded instead of acute. It resembles O. pinguis (Boeck), 

 but has the Lateral angles of the head much more broadly rounded, 

 the merits of the third perseopods less widely expanded, the margin 

 above the lower angle of the third abdominal segment smooth instead 

 of finely crenulated, and the lobes of the telson more diverging. It 

 has much larger eyes than O. minuta (Kr0yer) and quite different 

 first gnathopods. 



Genus VALETTIOPSIS," new. 



First antennae well developed with basal joint only moderately en- 

 larged and flagellum elongate. Mandibles with dentate cutting edge, 



Fig. 5. — Valettiopsis dentatos. oi, first antenna; do, second antenna; abi, 



FOURTH SEGMENT OF THE ABDOMEN; 1)1(1, MANDIBLE; MX!, FIRST MAXILLA; mx 2 , SEC- 

 OND maxilla; iii.ii>. maxilliped; t, telson; ur s , third uropod. 



secondary plate, spine row, and a well-developed palp opposite 

 the molar tubercle. First maxilla 1 with the inner plate furnished 

 with numerous plumose seta' along the inner margin; outer plate 

 with the distal margin oblique and armed with denticulate spines; 

 palp two-jointed and armed with short spinules on distal margin. 

 Second maxillse with subequal lobes, the inner setose along inner 

 margin as well as tip. Maxillipeds with well-developed inner plates; 

 outer plates armed with spines on inner margin, not reaching penul- 



■' Prom Valettia, ;i genus <>f Amphipods, and ti\}>is, appearance. 



