ISOPODS OF NORTH AMERICA. 



305 



FIG. 329. DYXAMENE 

 BENEDICTI. LAST 

 THORACIC SEGMENT 

 AND ABDOMEN. X 



m. - 

 This segment is 



FIG. 328. DYXA- 

 MENE BENB- 

 DICTI. SECOND 

 PLEOPOD OP 

 MALE (INNER 



BRANCH). X 



51f. 



first joint of peduncle longest; second and third joints about equal in 

 length; flagellum consists of six joints. Second pair of antennae 

 extend to the posterior margin of the second thoracic 

 segment; flagellum consists of about eleven joints. 

 The thoracic segments are of equal length. The 

 epimera are square with rounded pos- 

 terior angles. 



The penultimate abdominal segment 

 is crossed by suture lines, indicative 

 of coalesced segments. The terminal 

 segment is triangular, terminating pos- 

 teriorly in two teeth separated by a 

 narrow, rounded, funnel-shaped sinus, 

 very convex, and bears two longitudinal ridges on either 

 side of the median line. The uropoda do not exceed in 

 length the extremity of the terminal segment. Both 

 branches are rounded posteriorly and are similar in 

 shape and size. 



The type was collected by Mr. Heath at Monterey Ba}% 

 California, at the surface. Cat. No. 22570, U.S.N.M. 



This species is named for Dr. James E. Benedict, 

 assistant curator in the Division of Marine Invertebrates. U. S. 

 National Museum. 



Both sexes of this species are known, and are in the collection of 

 the U. S. National Museum. The male and female are alike in every 

 respect, with the exception that the inner branch of the pleopoda in 

 the male is provided with a stylet. 



51. Genus PARADYNAMENE, new genus. 



Second, third, and fourth articles of the palp of the maxillipeds not 

 produced into lobes. First article of the peduncle of the first antennas 

 with a long process at the upper end, which is acutely produced, and 

 extends to the extremity of the second article. 



Characters otherwise as in the genus Dynamene. 



Both sexes are known, the male and female being similar, but the 

 male is larger. 



PARADYNAMENE BENJAMENSIS, new species. 



Body oblong-ovate, twice as long as wide, 5 mm. : 10 mm. 



Head wider than long, 2 mm. :3 mm., with the anterior margin 

 widely rounded and produced over the basal articles of the antennae, 

 so as to entirely conceal them. The eyes are small, round, composite, 

 and situated in the post-lateral angles. The first pair of antennas have 

 the first or basal article large and elongated, with a long acutely ter- 

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