160 BRITISH PARASITIC COPEPODA. 



1. Tripaphylus musteli (P. J. van Beneden). 



(Plate XLV, fig. 6 ; Plate LI, fig. 1 ; Plate XLIX, 



figs 1-7.) 



1851. Lerneonema musteli P. J. van Ben. (12) vol. xviii, p. 287, pi. 

 Ko. 8, figs. 1-7, S & ? • 



1851. Lerneonema musteli idem. (11) vol. xvi, p. 125, pi. 6, figs. 11-14. 



1877. Lerneonema musteli Vogt. (142) p. 69, pi. iii, fig. 11. 



1878. Tripaphylus -musteli Richiardi. (103) p. xx. 



1885. Tripaphylus, musteli Carus. (29a) Pi'odr. faunae Mediterr., p. 372. 



1899. Lernseenicus viusteli Bassett-Smith. (8) p. 485. 



1904. Lernseenicus musteli A. Scott. (109) p. 41. 



1906. Tripaphylus musteli A. Brian. (21) p. 87. 



Female. — Body greatly elongated and slender, non- 

 segmented and with the surface quite smooth. Head 

 rounded and furnished with cartilaginous horns. 

 Thorax very slender, rather weak and somewhat 

 flexuous. Grenito-abdominal portion narrow at the 

 proximal end where it joins the neck, but becoming 

 gradually enlarged from the front backwards, and 

 assuming nearly the form of a spindle. Body pro- 

 vided posteriorly with two long slender appendages 

 nearly equal in length to the genital segment ; these 

 appendages, though in communication with the body- 

 cavity, have no connection with the egg-strings, which 

 have their origin immediately behind the base of the 

 prolongations referred to and are nearly twice their 

 length. 



Head with a considerable portion of the neck 

 buried in the tissues of the gill-arch of the fish. 

 Colour of the parasite deep red. Length as given 

 by van Beneden : Body exclusive of the abdominal 

 appendages 45 mm. ; abdominal appendages 15 mm. 

 in length and the egg-strings 23 mm. The body in 

 its greatest width measures 3 mm. — this specimen 

 wanted the head. The specimen figured here (PL LI, 

 fig. 1), which is also minus the head, measures 28 mm. 

 exclusive of egg -strings. 



Male. — The male of this species has the body 

 divided into two unequal portions : the anterior por- 

 tion is large, and carries three pairs of appendages — 



