APPENDIX. 293 



Stylus purpureus (page 24). 



"A fine specimen, about 8 inches long, had the spinous prolon- 

 gation extending about a quarter of an inch. This prolongation 

 appeared somewhat muricate under the microscope. Another speci- 

 men, 4 inches long, was of a deep red purple, all except the anterior 

 margin, which appeared yellowish. Its prolongation rather exceeded 

 a quarter of an inch. A thin specimen extended about 3 inches, and 

 the prolongation half an inch more. The colour of the anterior part 

 was dark purple, but about fifteen lines of the posterior, including 

 the prolongation, pure white. This latter portion had been undoubt- 

 edly a reproduction, as its commencement proved somewhat smaller 

 than the dark part, which was nearly two lines thick. The speci- 

 men came from Shetland. It must have been large originally. Very 

 faint circles were just perceptible on the body at considerable inter- 

 vals. In certain positions there is an indistinct appearance of annu- 

 lation in some of this flattened race." — Balyell. 



Stylus fragilis (page 24). 



This species forms a very slight silken sheath. The head tapers 

 almost to a point when the animal is in motion. "In quiescence, 

 the lower portion was much broadened. One or more enlargements 

 seemed often passing down the whole body from the anterior extre- 

 mity.'* — Balyell. Brittle. 



Stylus fasciatus (page 24). 



The anterior extremity is obtuse, " cleft by a groove ; posterior 

 extremity terminating in a spinous prolongation. Mouth (genital 

 aperture), a slit in the under surface of the anterior extremity. 

 Upper surface with two large black specks in front, and several 

 smaller ones behind them. Colour from light orange to reddish ; 

 the body encircled by a number of white belts. Margin of the ante- 

 rior extremity white.'* 



" In this species the spinous prolongation bears a great proportion 

 to the length of the body, sometimes being equal to a fourth part of 

 it ; and it is so flexible, that small specimens seem almost capable of 

 casting a knot on it. The number of belts is irregular, nor do I 

 know that they indicate anything but merely a diversity of colour." 

 — Balyell. 



Lineus longissimus (page 25). 



"It seems some very *low' Ascarid or Planarian worm. You 

 see it ? That black, shiny, knotted lump among the gravel, small 

 enough to be taken up in a dessert-spoon. Look now, as it is raised, 

 and its coils drawn out. Three feet — six — nine, at least, with a capa- 

 bility of seemingly endless expansion ; a shiny tape of living caou- 

 tchouc, some eighth of an inch in diameter, a dark chocolate-black, 

 with paler longitudinal lines. Is it alive ? It hangs helpless and 



