Miscellanea Zoologica. 69 



the membrane rises to the very apex and is comparatively broad, 

 but posterior to this the point of the filament is free, and still further 

 back the membrane gradually shortens until it at length is no longer 

 to be traced, — the branchiae at the same time becoming gradually 

 less, and ultimately obsolete on the caudal segments. (PI. II. fig. 

 12, 5, 6, 13.) When in water the branchiae are raised and extend- 

 ed, and in almost constant movement ; but when the worm is re- 

 moved from the water, they are laid across the back, their points 

 meeting in the middle, and give the body the appearance of being 

 marked with transverse folds or elevated striae. They are fringed 

 on both margins with a single series of vibratile cilia, discoverable 

 with a magnifier of common powers, but these cilia are deficient on 

 the apex, as well as on the lobe, while they extend over the dorsal 

 arch of the segments. (Fig. 3.) The head is furnished with two 

 large slightly tapering antennae which originate from the occiput, 

 and which are often cast off in the struggles of the animal : 

 they consist of two large central vessels filled with red blood, and 

 coated with a white mucous skin which, when magnified, appears 

 roughish or crenulate, and one side has a row of minute cilia, not, 

 however, to be seen except with a good glass. The antennae can 

 be directed to any point, and are capable of being rolled up in a 

 spiral form. (PI. II. Fig. 11.) There is a good deal of complexity 

 in the structure of the feet, which renders their description and 

 delineation difficult : they are lateral, and deeply divided in- 

 to a dorsal and ventral branch, which is compressed, and armed 

 with a series of retractile bristles of unequal lengths, and to 

 each branch there is affixed a rounded plain compressed lobe, pro- 

 bably a modification of the cirrus of other annelides. The bristles 

 are simple, curved, and acutely pointed, those of the dorsal branch 

 longer than those of the ventral, and there is a small fascicle of 

 longer ones at the root of the branchial filament. (Fig. 3.) The 

 feet are apparently alike along each side until within a few seg- 

 ments of the tail, when the branchial filaments become very short 

 or disappear, and the ventral branch seems to acquire a superior 

 developement, and to be armed also with longer bristles. (Fig. 4.) 

 The anus is dorsal in its aspect, and is surrounded with eight short 

 equal papillae, which assume a star-like form when the aperture is 

 dilated. 



The Nerines inhabit the sea shore, and the margins of our river, 

 a little below high-water mark. They prefer a soil composed of 

 sand and mud, and in which the latter rather preponderates. They 

 are found lurking under stones, or burrowing in the soil, and in the 

 latter situations, the surface to a great extent is seen full of small 



