Edmondson — Crustacea from Palmyra and Fanning Islands 33 



Heller's description of the type specimen is sufficient and complete in 

 most particulars but his accompanying figures are in many respects quite 

 inadequate. I am, therefore, presenting more complete figures of this 

 remarkable form and supplementing previous descriptions by some observa- 

 tions on the Palmyra specimens. 



In all of the specimens collected at Palmyra the rostrum has 8 teeth 

 on its upper border and 2 on its lower border. The mandibular palp is 

 rudimentary, so much so that without close scrutiny it may be overlooked. 

 No information is at hand regarding the mandibular palp in the type 

 specimen. Since the presence of this appendage is a family characteristic, 

 the condition of its development may possibly amount to a specific dififer- 

 ence. 



In the only specimen taken at Palmyra Island in which both of the 

 second walking legs are intact, the appendage on the left side of the body 

 is approximately one-fifth larger and longer than that on the right side. 

 No mention is made in any of the descriptions that I have seen, of an in- 

 equality in size and length of the second walking legs. More material is 

 necessary, I believe, to determine this inequality as a constant feature. 



Heller states that the hand of the second walking leg is somewhat 

 shorter than the arm segment. In the Palmyra specimens the palm is 

 slightly longer than the merus, the length of the two segments being in 

 the ratio of 4:3. 



The presence of a papilla on the dorsal extremity of the corneal area, 

 and a black pigment spot on the same side at the base of the cornea 

 characterize the eye in the Palmyra specimens. These features, if they 

 are present in the type specimen, are not mentioned in the description of it. 



The color of the type specimen is given as grayish-white, in preserved 

 condition. The Palmyra Island specimens, in alcohol, are pale yellowish- 

 brown. Heller reports the type specimen to be 9.5 lines in length. The 

 largest of the three specimens taken at Palmyra Island, an ovigerous 

 female, measures 35 mm. from the tip of the rostrum to the extremity of 

 the telson, with the abdomen straightened as much as possible. 



Apparently the only other species of the genus known is Hymenocera 

 picta Dana,^-* collected at Raraka Island, one of the Tuamotus. Dana's 

 figures were made from the living specimen which was, however, subse- 

 quently lost in the wreck of the "Peacock." 



The chief difference between Dana's species and Hymenocera elegans 

 is, as other writers have noted, in the greater expansion of the segments 

 of the third maxilliped in the latter. 



" Dana, James D., U. S. Expl. Exped., vol.' 13, Crust., p. 592, 1852 ; pi. 39, fig. 3. 

 a-c, 1855. 



