Miscellanea Zoologica. 73 



their function and structure being acknowledged to be identical, a 

 name expressive of any difference in either respect is liable to ob- 

 jection. They also describe the feet as composed of two branches, 

 but this is a mere anatomical fiction, for there is really no common 

 base and no bifurcation, the upper and lower papillee being separate 

 and divided by a considerable interspace ; and on the posterior seg- 

 ments these papillae are so slightly protuberant as to be scarce per- 

 ceptible. The bristles are of two kinds : from the superior papillae 

 there issue about six, three of them long and slender, and three shorter 

 and comparatively stout, — all of them simple, unjointed, and acute. 

 The bristles of the inferior papillee vary from three to one only in 

 the caudal segments, and they are all stout and curved like the 

 italic letter f. 



Plate III. Fig. 7- Cirratulus medusa of the natural size. 8. Head 

 and anterior segments much magnified. 9. A view of the mouth. 

 10. Transverse section of a segment from the posterior part of the 

 body. 11. A side view of two segments from near the middle, 

 shewing the spines greatly magnified. 12. The tail. 



In the Linnsean Transactions, Vol. ix. p. 110, Montagu has de- 

 scribed, under the name of Terebella tentaculata, a second 

 species of this genus ; and to make our essay as complete as our ma- 

 terials will allow, his description is here given in his own words. 



" Body long and slender, composed of more than two hundred 

 annulations, each furnished with two fasciculi of very minute 

 bristles : no eyes : branchiae obscure : from the sides issue very 

 long, red, capillary appendages, most numerous near the anterior 

 end, but the point or snout is destitute of them, and becomes more 

 acuminated, the mouth is placed beneath : the posterior end is also 

 obtusely pointed. 



" Length, eight or nine inches. 



" The colour of the upper part is olive- green, the under part dull 

 orange. 



" The lateral filiform appendages are continually in motion, ap- 

 pearing like slender red worms contorting in all directions round 

 the animal ; after death these usually curl up, when they first be- 

 come orange, and in a little time wholly lose their colour. 



" This curious species of vermes was taken from a piece of timber 

 that had been perforated by Pholades, and was destitute of any 

 natural covering. 



" It may be doubted whether the animal in question be nearest 

 allied to the Terebella or Nereis, or even whether it strictly belong 

 to either." 



