224 Dr. Johnston 07i the British Nereides. 



XXIV. — Miscellanea Zoologica, By George Johnston, 

 M.D., Fellow of the Royal College of Surgeons of Edin- 

 burgh. With Plates VI. and VII. 



The British Nereides. 

 [Continued from vol. iii. p. 295.] 



2. PiiYLLODOCE*, Savigny. 

 Char. Body linear-elongate, with numerous segments : head 

 distinct: proboscis thick, clavate, the orifice encircled with 

 papillary tentacula : no jaws : antennce frontal, small, four 

 or rarely five : eyes two ; tentacular cirri four on each side, 

 imequal, setaceous : feet uniramous, overlapped with a leaf- 

 like veined cirrus: bristles setaceous, slender, jointed: no 

 branchicE', posterior extremity terminated with a pair of short 

 fleshy styles. 



Observations. The Phyllodoces are the most beautiful 

 worms t among the Nereides, and are readily distinguished by 

 the series of compressed foliaceous lamellae, originating imme- 

 diately above the insertions of the feet, which garnish the 

 sides of the body. The peculiar office of these organs is con- 

 jectured to be respiratory J, but they also aid the animal in 

 its progress through the water, for, following the motions 

 of the feet and capable of being partially altered from a hori- 

 zontal to a perpendicular position, they act as a bank of oars, 

 and must be especially useful when the worm glides from a 

 solid surface, and finds itself unsupported in the water. Hence 

 the species are quick and lively, and swim with considerable 

 ease §. We have found them buried occasionally in light sand 

 between tide marks ; but they principally reside in deeper 



* The name of a sea-nymph, of the train of Cyrene. — Viig. Georg. iv. 

 336. It is synonymous with the Nere'tphylle of Blainville, but not with the 

 Phyllodoce of Ranzani. A genus of plants has been named Philodice, and 

 to those who think it against the canon to give the same name to any sub- 

 jects of Fauna and Flora, this might be a reason to prefer the nomenclature 

 of Blainville. 



f *' Virgines pulcherrimae inter Nereides." — Otho Fahricius. 



X Cuv. Reg. Anim. iii. p. 202. It would be wrong to overlook their re- 

 semblance to the branchiae in thelarvue of the Ephemerides : sec Reaumur, 

 Hist, des Insect, vi. p. 408, pi. 45, tig. 2. 



§ '* Currit egregie ; natare etiam valet lauiellis suis retroversis oblique 

 Eursum ereclis." — Fabr. Faun, Groenl. p. 298. 



