PSAMATHE. 183 



form, jointed, and issuing from a bulged base. Rings numerous, the 

 anterior shorter and smaller than the others, which are nearly of the 

 same length and breadth. Feet (fig. c) much developed and promi- 

 nent, all alike, conic, the apex emarginate, or divided into two obtuse 

 lobes, between which the bristles are protruded. Superior cirrus 

 elongate, filiform, white, jointed like a Conferva, scarcely moniliform, 

 and arising from a swollen basal joint ; ventral cirrus short, extended 

 or not beyond the apex of the foot, not jointed. Bristles (fig. d) all 

 compound, colourless, strong, the point fixed on the shaft like the 

 bill to the handle of a hedge-knife ; they are collected into two small 

 but unequal fascicles, having a rather small spine (fig. e) in the mid- 

 dle of each. Anal segment truncate, and terminated with two long 

 styles similar to the tentacular cirri. 



This little worm is occasionally met with in Berwick Bay, lurking 

 amid the roots of Confervae, corallines, and sponges ; or under small 

 stones in wet sandy soil. It advances through the water with con- 

 siderable velocity and in a wriggling manner, pushing out and alter- 

 nately withdrawing the bristles of its feet, and moving its long cirri 

 in every direction. When the creature is first taken and active, the 

 cirri have a somewhat moniliform appearance under the microscope, 

 but as its energy declines this appearance becomes fainter ; they then 

 appear jointed like a common Conferva; and, after death, even 

 these joints fade away, and the whole organ assumes a homogeneous 

 structure. 



When mature, I find that this worm attains the length of about 

 ly inch. If at rest, and in security, the colour of the back is a dirty 

 green, but there is a narrow band of a purplish-pink colour on each 

 side over the bases of the feet. Now let the worm be alarmed and 

 put in motion, and this purplish colour spreads instantly over the 

 whole body, rendering the worm very conspicuous. This phsenomenon 

 I noticed particularly in three fine specimens procured in April*. 

 To observe them more at leisure, I put them into a saucer of salt 

 water with some sand, and allowed them to remain over-night. In 

 the morning nothing was to be seen of one excepting a portion of the 

 anterior extremity. Unsuspicious of the truth, the two others were 

 not separated, and in about six hours afterwards one only was left : 

 he had, imitative of him who mars great Nature's plan, eaten his 

 neighbour up entirely, the neighbour being quite equal to himself in 

 size and strength. I hastened to preserve the cannibal ; but when 

 immersed in the spirits, he wriggled until he threw away nearly all 

 his cirri, and then he separated himself into several mangled portions 

 so as to render the body useless for even a coroner's inquest. 



Obs. Oersted correctly says that I had overlooked the jaws on 

 account of their minuteness and pellucidity, but they could not 

 escape the observation of my friend Mr. Dyster, whose figure of 

 them corresponds exactly with Oersted's description. The bristles 

 are in two small and unequal fascicles, with a small spine in the 



* Sir J. G. Dalyell says, — *' Colour of the finest specimens scarlet ; some are 

 yellowish ; but the colour is much dependent on the food. It feeds voraciously 

 on mussel, darting out its proboscis, and absorbing a great quantity. The colour 

 changes with the quality of the food." 



