208 ariciadjK. 



there can be no doubt that PoUicita is the same as SphcBrodorum of 

 Oersted, who has not been fortunate enough to see an individual ex- 

 trude the proboscis. 



1 . Sp. peripatus, between each pair of the wart-hke branchiae two 

 small papillje. Length 2". Plate XIV. figs. 1-6. 



Bebryce peripatus, Johnston in Rep. cit. 2/3. 



PoUicita peripatus, Johnston in Ann. Sf- Mag. Nat. Hist. xvi. 6. pi. 2. 



f. 1-6. 

 Nereis bnllata — the Knob Nereis, Dalyell, Paw. Great, ii. 147. pb 22. 



f. 1-5. 

 Sphajrodorum peripatus, Gruhe, Fam. Annel. 67. 



Hah. The coralline region. 



Desc. Worm about 2 inches long, very slender, narrowed towards 

 both extremities, almost cylindrical, of the usual yellowish-brown 

 colour, roughish. Head small, indistinctly separated from the fol- 

 lowing segment, longer than broad, rounded in front, where there 

 are three unjointed antennae, the medial nearly as long as the lateral : 

 on the sides of the head there are besides a few minute fleshy papillae, 

 and the feet advance on each side rather before the eyes, which are 

 placed unusually backwards. Eyes small, four, the anterior pair 

 most approximate. Mouth inferior. Proboscis large, smooth, eman- 

 dibulate, the orifice plain. Segments numerous, about the length of 

 their own diameter, each of them furnished with a globose branchial 

 tubercle on each side placed over and above the foot, immoveable, 

 unjointed, smooth, with a small papillary tip. Feet about sixty 

 pairs, one pair to every segment, conoid, uniramous, papillary, not 

 projecting beyond the branchiae when at rest, but capable of being 

 protruded beyond them, armed with four or five bristles and a spine. 

 The bristles simple, sharp, curved like a hedge-knife, retractile. The 

 skin is covered with minute papillae or granules, only visible under a 

 high magnifier. Anal segment truncate, without styles, but on each 

 side there is a mammillary foot, which is larger than the penultimate, 

 and, like it, appears to be destitute of bristles. 



The specific name of the worm was suggested by the resemblance 

 it has to the Peripatus juliformis of the Rev. L. Guilding {Zool. 

 Journ. ii. pi. 14). It is slow in its motions. In some positions, 

 what appeared to be a minute antenna was visible on the top of the 

 head, and such as our figure represents it ; but I could not satisfy 

 myself of its real nature, and the appearance may have been pro- 

 duced by a mere fold, or possibly by some refraction of the light. 

 The areolated structure of the branchiae seems to be peculiar ; and a 

 foot bristled with papillae is a very rare formation among the Anne- 

 lides errantcs. 



Our figures were taken from a specimen which was only 8 lines in 

 length. 



Obs. I am not satisfied that this is distinct from the Sp.Jlavum 

 of Oersted, but I have not met with a specimen of *S^. peripatus 

 since I became acquainted with the latter species. In one small 



