EFFECT OF LINES ON ASCIDIANS AND SHELL-FISHES. 49 



penetrating the tough tests of the latter (Ascidians) as the 

 lines are carried by the currents. Only from the liners are 

 the curious and rather rare ' sandy-nipples ' (Pelonaia) pro- 

 cured — another of the remarkable forms characteristic of St 

 Andrews. Hundreds are sometimes brought on shore, the 

 drifting hooks having penetrated the thinner superior part 

 of the test as the creature was plying its respiratory and 

 nutritive currents on the bottom. None have yet been ob- 

 tained from the trawl, for the ground is rough. The multi- 

 tudes of dead shells brought up by the liners have been one 

 of the richest fields for the encrusting forms of the Polyzoa — 

 such as Lepralia, the foliaceous — as Eschara and Retepora, 

 and the more or less ramified Cellepora and Serialaria. 



When we come to the group of the shell-fishes or mollusks, 

 the great variety that have been obtained from the hooks of 

 the liners for hundreds of years is noteworthy. No collection 

 of marine shells, worthy of the name, and made long before 

 trawling was introduced into Scottish waters, exists — but is 

 a standing proof of the fact that the hooks are almost as 

 effective in furnishing rare specimens as the trawl. Some of 

 the smaller forms, indeed, are more surely obtained in this 

 way than by the trawl. Many are found in the debris 

 attached to the masses of horse-mussels so frequently brought 

 up from the bottom, others are fixed to dead valves of the 

 larger shells, or have their siphons, foot or other parts, pierced 

 by the hooks. On the zoophytes brought up by the lines, such 

 naked forms as Doto, and, on Alcyonium, Tritonia plebeia are 

 found in numbers, while the larger Tritonia Hombergii, " a sea 

 lemon," is occasionally pierced by a hook as it drags over the 

 bottom. The active cuttle-fishes do not seem to be frequently 

 caught by the hooks, though, when attacking the fishes on the 

 lines, or interfering with bait, an arm or other part is now and 

 then fixed. In contrast with the trawl, however, few cuttle- 

 fishes are captured by the lines. 



It is by no means to be supposed from the foregoing remarks 

 that any blame is to be attached to the liner for interfering 

 with the bottom-fauna. The notion would be unwarrantable. 

 In the course of his operations the forms indicated have been 



M. R. 4 



