560 On Species of Ampkipoda. 



low tide abont 3 feet. The contents of the bag were sent to 

 me for examination, and were found to contain no less than 

 19 species of Anipliipods. Among these were about 40 

 female Corophium honelli., M.-E., 3 female C. crassicorne, 

 and 3 males — of which s])ecies? 1 may say here that I take 

 G. O. Sars's descriptions and figures (i) as the correct repre- 

 sentations of these species as far as they go. 



Now there is a mystery about the male of C. honeUii. G. O. 

 Sars (i) says he has "never met with males of this form." 

 Norman (2) says that "Among some hundreds of specimens 

 loosely examined there were none which at a glance would 

 seem to be males." In 1879 Dr. P. P. C. Hoek (3) described 

 and figured the antennae of a male and female Corophium 

 under the name of C. crassicorne — presumably they were 

 taken in the same locality. 



Now a comparison of these figures with those of Corophium 

 acherusicuni, Costa, in Delia' Valle's ' Gammaridea of the 

 Bay of Na|)les ' (pi. viii. figs. 24, 31, &c.) shows that they 

 are identical as regards the female, and, as far as can be 

 judged from the portion of the lower antenna shown by 

 Hoek, |)robably the male also. This identity was suggested 

 by Stebbing (5), and has been confirmed by an examination 

 of specimens trora Bone, Algeria, kindly sent to me by 

 Mons. E. Chevreux under the name of (J. acherusicum, 

 Costa (1857), which, therefore, merges in the older name of 

 C. honcllii, Milne-Edwards, 1830. 



As regards C. crassicoriie, Bruzelius, while the female 

 lower antermas differ entirely from those of C. bonellii (as is 

 well shown by Sars), the males are far more difficult to 

 distinguish. Chevreux (6) says that the males of C. acheru- 

 sicum and C. crash'icorne are difficult to distinguish except by 

 the lateral angles of the head, obtuse and crenate at tiie 

 extremity in tiie former, much produced and acute in- the 

 latter. UMfortunately this feature is difficult to see, and as 

 the two species are found associated on our western coasts 

 and the females of C. bomllii exceed the males numerically 

 to an almost incredible degree, it is no wonder that the latter 

 have been attributed to C. crassicorne. The tooth on the 

 inner side of the third joint of the peduncle of the lower 

 antennae and the number of spines on the first joint of the 

 upper antennai in the male, which in 1898(7) 1 thought 

 distinctive, appear to be variable characters. 



To the synonymy of C. bonellii given in the Gammaridea 

 of ' Das Tierreich ' must therefore be added C. acherusicum, 

 Costa, and C. crassicorne^ Hock. My C. honnellii in Trans. 

 Linn. tSoc, 2ud ser. vol. xii. p. 343, should be C. bonellii, 



