538 Miscellanea Zoologica. 
9. N. rufifrons, of a yellowish colour verging on rose-red anteri- 
orly; mouth dark red ; eyes none ; body very slender. (PL 
XVIII. Fig. 5.) 
HAB. Under stones between tide-marks, in Berwick Bay, fre- 
quent. 
When fully stretched out in creeping, this worm is fully two inches 
long, but very narrow and filiform, or rather tapering to a point 
posteriorly ; it is of a yellowish colour for the greater part, but the 
anterior extremity is a rose-red, while the apex or mouth forms a 
dark red speck. When slightly compressed between plates of glass 
the intestine may frequently be seen unrolling itself from the cir- 
cular and terminal mouth in the manner that some annelidans un- 
roll their proboscis. The worm will thus sometimes nearly disem- 
bowel itself. The intestine is white, round and filiform, without 
any appendage. 
, r ; Explanation of Plates. w -?> 
Plate XVII. Fig. 1, Nemertes gracilis of the natural size. 
1. * Anterior portion of the same magnified ; Fig. 2, 2, N. lactiflo- 
rea, both figures of the natural size. 2. * Anterior portion mag- 
nified. 2 * * Caudal extremity magnified, shewing the ova exte- 
rior to the coeca ; Fig. 3, N. lactiflorea, var. brunnea. 3. * 
The head magnified ; Fig. 4, N. quadrioculata, natural size ; 
Fig. 5, N. melanocephala, natural size. 5. * The same magnified ; 
Fig. 6, N. pulchra, natural size. 6. * The head of the same mag- 
nified. 
Plate XVIII. Fig. 1, 1, 1, Nemertes (B.) olivacea, of the natu- 
ral size. 1. * The anterior and middle part magnified. 1* * Em- 
bryo young ? of the same contained in the body of some specimens. 
Fig. 2, Nemertes (B.) octoculata, natural size. 2. * The anterior 
portion magnified ; Fig. 3, Nemertes (B.) purpurea, natural size. 
3. * The head, and a portion of the middle, and the tail magnified, 
shewing the ova within a kind of vesicle. Fig. 4, Nemertes (B.) 
rufifrons, natural size. Fig. 5, A portion of the anterior extremity 
magnified. 
Of the wood-cut Figs. 1, 2, represent the stomach and a portion 
of the intestine of Nemertes lactiflorea ; 3, and 4, of the N. pul- 
chra ; 3, shewing it previous to being compressed, 4, after being 
compressed between plates of glass. 
