140 BRITISH PARASITIC COPEPODA. 



Male. — Slender, elongated, becoming gradually at- 

 tenuated posteriorly. Body distinctly segmented, rings 

 free and mobile. First segment of the cephalothorax 

 scutiform, about as broad as long and equal in length 

 to the next two segments taken together ; third seg- 

 ment larger than the second and armed with a strong, 

 slightly curved spine on each postero-lateral angle. 

 Abdomen slender ; anal segment longer and narrower 

 than any of the preceding segments. Caudal rami 

 very slender, elongate, rather shorter than the anal 

 segment, and provided with two apical setae. 



Antennules very slender and consisting of six indis- 

 tinct joints. Antennae moderately stout, two- jointed, 

 and furnished with two terminal, slightly hooked setae. 

 In the first maxillipeds the basal part is greatly 

 enlarged and bears strong claw-like terminal spines ; 

 the second pair are small and feeble. Locomotary legs 

 two pairs, short and biramose ; both pairs have the 

 outer ramus two- and the inner one-jointed ; the rami 

 are subequal in length but the outer ramus is rather 

 more robust, and the proximal joint is very short; 

 both pairs are liberally supplied with spines and setae. 

 Length about 4 mm. 



Habitat. — Living freely in the mucous canals in 

 the head of the sword-fish (Xiphias gladius): On a 

 sword-fish captured off Lowestoft in 1892 ('Cambridge 

 Natural History,' vol. iv, p. 73, footnote). 



Distribution. — Mediterranean. New Zealand (G. M. 

 Thomson). 



Dr. S. F. Harmer, who examined the sword-fish and ob- 

 tained the specimens of Philichthys described above, has sent 

 us the following note, which he kindly permits us to use :- — 



" Some years ago (1892), when examining a specimen of 

 sword-fish which had been taken off Lowestoft, it occurred to 

 me to look for Philichthys xiphise, which 1 readily found in the. 

 place in which it has been described as occurring, namely, 

 in the frontal bones. ... I speak from memory, but I 

 think I am right in saying that one of the parasites was found 

 in each frontal bone." — (8. F. Harmer.) 



