258 MISCELLANEOUS. 



and tapers slightly downwards, divided into about 80 to 110 very dis- 

 tinct segments, the last the extremity, which is obtuse. Six or seven 

 flexible contractile tentacular organs, two of them long and more active 

 than the rest, together with six or eight, sometimes more, long, slender 

 bristles, all issue from the anterior extremity. The whole of the appa- 

 ratus is retractile within the body, like the arborescent tentacula of the 

 Holothuria. 



The segments are more cylindrical, and more deeply divided from 

 each other than in most of the Annelides. 



The surface of the skin is wholly granulated, covered with tubercles, 

 and like shagreen. A row of pencils, composed of several bristles, be- 

 long to the segments ; besides which, there are some curving spines. 

 This animal is sufficiently active at night, crawling over the bottom of 

 its vessel. During the day it lurks between shells among mud, or under 

 them, where it may remain a long time without shifting. The two 

 longer tentacula, which much resemble those of the preceding animal, 

 protruding far, and searching around with lively action. It shuns the 

 light. The body is of a brownish or earthy appearance, the two longer 

 tentacula pale or yellowish, the others green. 



If the animal constructs a tube, it is of the slightest and most inde- 

 finite description. I have never seen it, either in its natural abode, which 

 is both littoral and in deeper water. Specimens have survived many 

 months. 



An ovarium, with deep grass-green ova, protruded from the body, 

 with spherical ova, fig. 9. 



PLATE XVIII. 



FIG. 5. Pherusa Mulleri. 



6. Transverse section, enlarged. 



7. Section shewing the spines of the body, more enlarged. 



8. Bristles of the anterior, enlarged. 



9. Ova, enlarged. 



