344 MARKETABLE BRITISH MARINE FISHES 



3. The Butterfly Blenny. — Front part of the dorsal fin 

 elevated, and having a deep black spot, surrounded by a 

 white ring. 



4. Montague's Blenny. — Having a fold of skin between 

 the eyes, fringed with small tentacles. 



II. Species without any division in the dorsal fin ; caudal 

 separate ; throat-fins very small ; small scales present ; two pairs 

 of tentacles on head. 



5. YarrelPs Blenny. 



III. Species in which the body is elongated with a single low 

 dorsal fin, and the tail-fin not separate. 



6. The Gunnel or Butter-fish. — Body long and slender ; 

 a row of black spots with a white ring round each along 

 the base of the dorsal fin on each side. 



7. The Viviparous Blenny Body tapering towards the 



tip of the tail, and a long notch in the edge of the dorsal 

 fin at the tail end. 



IV. Species of large size, with tail small and separate ; no 

 throat-fins ; scales rudimentary. 



8. The Sea-cat, Wolf-fish, or Cat-fish. 



At St. Andrews Mr. Holt saw the spawning of the butter-fish 

 or gunnel in the aquarium in February. The eggs were adhesiv^e, 

 and the parents were seen to roll the mass of eggs into a ball by 

 coiling their bodies round them, not both parents together, but 

 the male and female in turns. It has been observ^ed by Professor 

 Mcintosh and Mr. Anderson Smith that in the natural condition 

 the parents are found coiled round the balls of spawn, which 

 are somewhat larger than walnuts, and not attached to anything. 

 The spawn is shed from the middle of February to April. 



The blennies proper all attach their eggs in a single layer over 

 the sides of cavities between stones or in rocks, but it has not 

 been observed with certainty whether it is the male or the 

 female that guards and tends them. A large hollow bone, 

 probably from the leg of an ox, on the sides of the cavity 

 of which were attached the eggs of the butterfly blenny, was 

 examined by me at Plymouth. A specimen of the fish was 

 found in the cavity, and it was probably the male, but I did 



