GEN. ZOARCUS. THE VIVIPAROUS BLENNY. 265 



to have separated them without infringing upon a 

 most natural arrangement. Their ventrals have 

 three rays, all soft ; and their dorsal and anal unite 

 at the caudal, so surrounding the extremity of the 

 tail. Behind the vent they have a small papilla, the 

 prolongation of the somewhat thickened skin round 

 the two openings of the oviduct canals. During 

 spawning-time this papilla swells, elongates, and 

 somewhat assumes the appearance of the male ap- 

 pendage of certain of the viviparous fishes already 

 alluded to (see p. 64) ; but whether examined 

 externally or internally, it is nothing more than the 

 appearance without the reality. One species alone 

 belongs to Europe, and two or three to America. 



(Sp. 70.) Z. viviparus. (PL XIX.) The Vivi- 

 parous Blenny derives its chief interest from its ovo- 

 viviparous character, on which we have already so 

 largely dwelt. Its specific characters need not oc- 

 cupy us long. The colour of the back and sides is 

 yellowish brown mottled with dark olive; when 

 young, the lateral line, and parts beneath, are spotted 

 with white ; but this is not seen in the adult. The 

 length usually assigned to it is six or eight inches ; 

 but Dr. Neill has seen it attain fifteen inches, and 

 Dr. Parnell tells us that specimens have been taken 

 at the mouth of the Tweed which measured nearly 

 two feet. Its habits are very similar to those of the 

 other members of the family, being seen mostly 

 near low-water mark, among rocks and weeds. 

 Mr. Low mentions, that when he first observed 

 that they brought forth their voung alive, he put a 



