REPORT ON THE CRUSTACEA MACRURA. 00i> 



with the figures given by Anton Dolirn * and also that figured by Claus, 2 but each of these 

 authors shows that the external rod is only a branch of the basal joint, which is I presume 

 the second or basisal joint, and neither gives the outer foliaceous branch, although Anton 

 1 )ohrn shows the rudiment of such, unless it be the fragment of a ruptured appendage, 

 and he moreover figures what I believe to be a basecphysis with four small terminal 

 articulations. Claus represents the same organ as being multiarticulate for two-thirds 

 of the entire length, whereas Milne-Edwards figures it as being uniarticulate, which 

 corresponds more nearly with my own observation, since, although I saw indications of 

 there 1 ning three, the articulations appear not to have been fully formed, but only 

 defined by the presence of marginal cilia. 



The six pairs of pereionic appendages represent the two pairs of gnathopoda and four 

 pairs of pereiopoda ; these all correspond in general form, but differ a little in size and 

 ornamentation, they are all six-jointed and have a long basisal joint, which carries a 

 long multiarticulate ecphysis attached to the distal extremity. All, excepting the first 

 gnathopod and the posterior pereiopod, are furnished with a strong tooth near the 

 middle of the basisal joint, as well as with one on the anterior distal angle of all except the 

 posterior pair, and with three or four others on the next succeeding joint (ischium) in 

 all except the first and last pairs of appendages. Now, these tooth-like prominences are 

 too numerous and conspicuous to be overlooked, and since they are not shown by Milne- 

 Edwards on the basis in either of his figures, while he shows them on the ischial joints 

 of all excepting the first and last pairs in his figure in the first-quoted work, and as 

 Claus represents his species as having the appendages smooth throughout, excepting the 

 second pair of gnathopoda, which is armed with a strong tootb on the anterior distal 

 angle of the basis and one on the anterior margin of the ischium of the same pair, I 

 am inclined to believe that it is possible there may be a greater amount of specific 

 separation between the several specimens observed than has generally been supposed, 

 although the instances of variation in what I believe to be specimens of the same 

 species induce me to hesitate until further opportunity may decide. 



The branchiae (fig. lbr) are now beginning to make their appearance in the form of 

 small plumes within sacs attached to the coxa of the second pair of gnathopoda and the 

 first pair of pereiopoda. 



The pleopoda are also becoming visible as incipient buds ; there is a pair at the 

 postero-lateral angles of each somite excepting the first ; that on the sixth somite 

 being already in a well-advanced condition and taking its character as a permanent 

 part of the rhipidura of the adult animal. 



In the Western Pacific, north of New Guinea, three other specimens were obtained 

 that are 25 mm. in length. One of these was labelled by Dr. von Willemoes Suhm 



1 Loc. cit, pi. xv. tig. 5. 2 Loc. cit, pi. viii. fig. 10. 



