52 



moderately long and narrow, and equal to the combined 

 lentjths of the last three abdominal segments. 



One specimen in a snrface collection from Bahama 

 Bank, March 7th, 1905. 



This new species has a general resemblance to the 

 type G. callianassae, but differs in having a more slender 

 fifth foot, which has two marginal spines on the second 

 joint instead of only one as shown by Canu, and by the 

 shorter furca. The furca in Canu's species are nearly as 

 long as the whole abdomen. 



The species is dedicated to the memory of my 

 colleague, I. C. Thompson, who studied the Copepods of 

 Liverpool Bay for many years with marked success, as 

 shown by his numerous reports on the subject. 



(18) Caligus scomberi, Bassett Smith. Plate Y. 



This parasite is occasionally found when examining 

 the gill chambers of mackerel, and has already been 

 recorded for the district. C. li. Wilson in Part I. of his 

 work on the North American Parasitic Copepods* is 

 inclined to doubt the validity of this species and the 

 accuracy of the figures given by British authors. It 

 appears desirable, therefore, that figures of the form from 

 the Irish Sea should be given. We have not yet been 

 fortunate enough to find the male, and the illustrations 

 give the characteristic features of the female only. The 

 parasite measures 5"57 mm. in total length, and the 

 abdomen is composed of a single joint. There is a decided 

 contraction near the distal end, but no trace of a division. 

 The fourth feet are similar in structure to other Caligi, 

 and have a basiopodite with a three-jointed exopodite. 

 Sternal fork slender, sides rounded and tapering to a 



* Proceedings of the United States National ]\[useum. vol, 

 xxviii., pp. 479-672 (reprint No. 1404), 



