144 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 121 



Discussion. — Wilson (1905b) suggests that Caligus pelamydis 

 Kj0yer, and C. scomberi Bassett-Smith are synonymous but they 

 were not synonymyzed until 1913 (Scott and Scott). Guiart (1913), 

 however, feels that there is some evidence for maintaining both 

 species. In comparing the two, he states: "Cette espece [C. pelamy- 

 dis] est beaucoup plus volumineuse que la precedente [C. scombri, 

 T. Scott's (1901) modification of Bassett-Smith's C. scomberi], le 

 segTiient genital beancoup (sic) plus long et Fabdomen nettement 

 forme de deux segments. Beaucoup d'autres caracteres s'opposent 

 du reste a la fusion de cette espece avec la precedente, conmae le 

 voulait Wilson (8, p. 596)." Scott and Scott (1913, p. 59), however, 

 state: "We think there can be no reasonable doubt that the form 

 obtained by Kr0yer on Pelamys sarda, and described by him in the 

 work referred to under the name of Caligus pelamydis, is identical 

 with that from the mackerel [C. scombri]; the general structure of the 

 animal, the shape of the sternal fork and of the genital segment, and 

 the structure and armature of the fourth pair of thoracic legs, are 

 similar in both forms." A comparison of specimens of these species 

 in the U.S. National Museum suggests, to the present author, that 

 the two are synonymous. 



Caligus pelamydis is most readily distinguished by the nature of 

 the fourth thoracic leg. The shape of the female genital segment 

 is variable. In some of the specimens in the U.S. National Museum 

 (USNM 74284 and 74358) the lobate condition of the posterior end 

 of the genital segment is present, as shown in figiu-es 52a,c, while 

 in others the lobes are reduced or absent. 



The fourth thoracic leg is complex, the armatiu-e elements are 

 poorly defined, and, in most cases, lightly sclerotized. The figure 

 given by Wilson (1905b, pi. 13: fig. 161) does not show the frilled 

 membranes adjacent to the bases of at least the fu'st 2 spines and does 

 not show the fine accessory projection at base of the second spine 

 that was evident in a stained mount of the leg made from a specimen 

 ui the USNM collection. 



Caligus kanagurta Pillai, 1961, exhibits a very close similarity to 

 C. pelamydis. The fourth thoracic leg, however, is figured as having 

 three small, plumose spines on the distal segment which are not 

 present in C. pelamydis. 



Caligus longipedis Bassett-Sinith 



Figures 54-56 



Caligus longipedis Bassett-Smith, 1898b, p. 359, pi. 10, figs. 2-3. — Yamaguti, 



1963, p. 56. 

 Caligus longipes Bassett-Smith, 1899, p. 452. — Wilson, 1905b, p. 556 (in key). 



I 



