302 



BULLETIN 54, UNITED STATES NATIONAL MUSEUM. 



Type.C&t. No. 22571, U.S.N.M. 



Both sexes of this species are known, the two forms resembling each 

 other in every respect, with the exception that in the male there is a 

 stylet on the inner branch of the second pair of pleopods. 



Prof. S. J. Holmes writes that the sexes do not show any marked 

 dimorphism. He also admits the following:" "An examination of 

 several specimens of the species showed that the males present no 

 appreciable external differences from the females except that, as a 

 rule, they are of somewhat larger size." 



Specimens of both sexes are in the collection of the U. S. National 

 Museum. The inner branch of the second pleopod of the male is 

 figured. 



DYNAMENE ANGULATA Richardson. 



Dynamene angalata RICHARDSON, Proc. U. S. Nat. Mus., XXIII, 1901, pp. 534-535. 

 Locality. No Name Key, Florida. 

 Found among algas at low tide. 

 Surface of bod} 7 smooth; color yellow. 



Head large, with small median point on its anterior margin. First 

 pair of antennae reach the posterior margin of the second thoracic 

 segment; flagellum composed of nine joints. 

 Second pair of antennae reach the posterior mar- 

 gin of the fourth thoracic segment; flagellum 

 composed of thirteen joints. 



The thoracic segments are subequal in length, 

 the first being a little longer than any of the 

 others. The epimera are broad and short, with 

 acute lateral angulations. 



The first abdominal segment bears suture lines 

 indicative of coalesced seg- 

 ments. There are three small 

 tubercles in a transverse row, 

 one median and one on either 

 side. The terminal segment is subtriangular, with 

 the extremity produced and deeply excavate, the 

 excavation being like an inverted V. At the base of 

 this segment are three large tubercles in a transverse 

 row, the median one being long and very acute, 

 the lateral ones rounded. The branches of the 

 uropoda are similar in shape, the outer one being somewhat longer; 

 they are obliquely truncated with the outer posterior angles acutely 

 produced and do not quite reach the tip of the abdomen. 



Specimens were found by Mr. Henry Hemphill at No Name Key, 

 Florida. 



Type. Cut. No. 23906, U.S.N.M. 



FIG. 323. DYNAMENE ANGU- 

 LATA. MAXILLIPED. x 



sat. 



FIG. 324. DYNAMENE 

 ANGULATA. ABDO- 

 MEN. 



"Proc. Cal. Acad. Nat. Sci. (3), III, No. 11, 1904, p. 304. 



