122 TESTACKIXA SCUTULUM, SOWERHV. 



in it is made more pronounced, and the ribbon being tightened the 

 backwardly-pointing teeth on the outsides of the " spoon " stand up- 

 right, while the barbs of those on the opposite edges come nearer to 

 one another with an action resembling that of a steel trap. Should 

 an earthworm be near enough the barbs pierce and hold it, but the 

 victim got away in some cases where its end was not entrapped ; 

 otherwise the slug extends itself once more, enveloping the worm 

 completely, if its size allow. The general conclusions arrived at are, 

 that Testacella does not necessarily feed only at night : that it is 

 doubtful the slug stalks its prey at all, and that the strikingly rapid, 

 but more or less automatic, protrusion of the radula has given rise to 

 the fanciful stories of its crouching and springing. Again, the end of 

 the worm must as a rule be seized, for apart from other considera- 

 tions it is impossible for a large worm to be swallowed in any other 

 way, as two thicknesses would have to be taken in together. A way, 

 however, strikes one by which this last difficulty might be got over, 

 and this is hinted at by one of the authors quoted from in the paper, 

 namely, granting that a worm could be securely held by the middle 

 it might well get broken in half, and one portion becoming free the 

 other might be swallowed in the ordinary way ; whether the second 

 half would afterwards be attacked is a question. The results are 

 summed up as follows : — ■ 



" It will be seen that Testacella is particularly well adapted for 

 catching its prey should it meet them in the mouth or other portions 

 of their tunnels. The slug on coming into contact with the head of 

 an advancing earthworm, appearing above ground, or what not, would 

 contract, and, shrinking back, would entirely block the way with 

 its now swollen body. The worm in endeavouring to proceed would 

 continue to irritate the surface of the slug, seeking the groove above 

 the slug's mouth — in some cases small worms actually managed to 

 force their prostomia into the oral aperture — and would be caught in 

 the grip of the radula as it was shot out, and held securely, the slug 

 maintaining, by its broadened body, a firm hold on the walls of the 

 burrow. This method of procedure would not, of course, prevent 

 the Testacella from attempting to secure worms in the open, its 

 stealthy movements not alarming the latter in any way, but it would 

 not be so certain of a meal, as the chances of a successful hit with 

 the radula are by no means so great." 



The paper winds up with some remarks as to the specific dis- 

 tinctness of Testacella scntulion, Sow., which, apparently owing to the 



