26 PROCEEDINGS OF THE NATIONAL, MUSEUM. vol.60 



attached to one of the gill arches. In addition to the fact already 

 noted that the imbricated foliaceous laminae enclosing the posterior 

 body of the female and covering the sides and ventral surface of the 

 male are found in no other copepod ; the color of these laminae is also 

 peculiar. The grayish-white background is thickly sprinkled with 

 minute circular dots and irregular lines, which, being transparent, 

 appear darker in color. 



The species has been described and figured many times, but the 

 female has thus far succeeded in absorbing all the attention and 

 no figure of the male has appeared. The foliaceous legs of the male 

 are of peculiar interest by reason of the presence of rudimentary 

 rami upon the first two pairs, which do not appear in the female 

 (figs. 7 and 8). 



Genus NORION Nordmann. 



Norion Nobdmann, Bull. Soc. Imp. des Nat. Moscou, vol. 37, 1864, p. 488. 

 Norion Bassett-Smith, Proc. Zool. Soc. London, 1899, p. 469. 



Generic characters of female. — General body form an ellipsoid, 

 flattened dorsoventrally, both surfaces covered with subconvex shields. 

 Head fused with the first thorax segment and the two distinctly sepa- 

 rated from the rest of the body by a short neck ; the remaining thorax 

 segments fused inter se; no abdomen. Dorsal carapace divided into 

 anterior and posterior portions by deep lateral incisions, the anterior 

 part projecting forward as a narrow, pointed wing on either side of 

 the cephalothorax, the posterior part evenly rounded. Ventral 

 carapace divided into right and left halves, anteriorly by the cephalo- 

 thorax, posteriorly by a deep median incision, each half with a 

 median longitudinal keel. 



First antennae filiform, six-jointed ; second antennae with a swollen 

 basal joint and a powerful, curved terminal claw ; first maxillae two- 

 jointed, apparently setiferous; second maxillae and maxillipeds also 

 two- jointed but uncinate. A pair of rudimentary first legs at the pos- 

 terior margin of the cephalothorax, mere curved pads without rami. 



Type of the genus. — Norion ewpansus, monotypic. 



Remarks. — This genus was established by Nordmann upon a single 

 female specimen taken from the inside of the gill cover of an im- 

 known fish at Honolulu. He located the genus in the family Chon- 

 dracanthidae near the genus Tucca. No investigator besides Nord- 

 mann has ever seen this genus, and none except Bassett-Smith has 

 ever mentioned it. He recognized that it was not a Chondracanthid, 

 and placed it in the present family, but he still retained Nordmann's 

 idea that it was closely related to Tucca., and so he transferred that 

 genus to the Dichelesthiidae along with Norion. The two genera, 

 however, have nothing in common ; in volume 39 of these proceedings 



