232 



HARDWICKE'S SCIENCE-GOSSIP. 



continue on every segment as far as the tail ; there 

 are three antenna, and two large palpi ; the proboscis 

 carries two pairs of sharp horny teeth .which work 

 vertically, its aperture bristles with an array of warty 

 tentacles, and its inner surface is villose and highly 

 vascular ; there are three bunches of bristles on each 

 foot, and at least four shapes of bristles, some quite 

 smooth, some serrated on the upper half or on both 

 sides for a short way down, while others are double- 

 jointed, or bear a kind of claw at the end, &c. 



The genus Polynoe comprises a series of forms, 

 some of which are among the commonest of shore- 

 haunting fauna. Overturn or displace any stone 

 about low-water mark, and you will discern one of 

 these scale-clad creatures wriggling away into a place 

 of protection and obscurity. The two longitudinal 

 nerve chords run close together, but are not so fused 

 as in Nephthys, &c. The peritoneal fluid is very 

 abundant, yet but little corpusculated, while the 

 blood-proper is comparatively insignificant, there 

 being no proper vascular system. We must here 

 indicate two important anatomical features about the 

 genera of annelids we are now reviewing : — (i) The 

 conspicuous scales are not true gills, but only organs 

 specially designed to generate branchial currents for 

 the oxygenation of the peritoneal fluid within the 

 body ; (2) the stomach dilates on each side into a 

 number of pouches or blind sacks, with muscular 

 orifices, and always filled with a dark -green chyme, 

 and bearing on their exterior the oil-filled glandules 

 of the true liver. It has been supposed that the 

 oxygen, infused by the action of the scales into the 

 peritoneal fluid acts on this stored-up chyme, and by 

 its medium replenishes the true blood itself. The 

 ■proboscis of Polynoe is exceedingly well developed, 

 and is of the structure already sketched under the 

 preceding species ; there are any amount of antenna;, 

 palpi and cirri along the body, all being organs of 

 touch, the latter specially developed and solid and 

 unciliated ; there are one or two pairs of eyes ; the 

 bristles and spines are strong, very large, and beauti- 

 fully constructed. P. squainata frequents the shore, 

 but is common in deep water ; it has twelve pairs of 

 fixed scales which are ciliated on their outer margin, 

 and the two last scales are excavated for the anus ; 

 the tentacles and their cirri are thickened below the 

 point ; the bristles are very beautiful, those on the 

 upper branch of the foot are ranged in two rows, or 

 hinds of somewhat similar structure, each having a 

 thick round blade tapering to a fine point and trans- 

 verse serrated ridges on its convex side, those of the 

 lower division having a long handle and a short- 

 pointed slightly curved blade bearing eight or nine 

 transverse serrated ridges on its lower half; this species 

 is sluggish and dilatory in movement. P. cirrata is 

 one of the commonest sea-worms of the shore; it is 

 more vivacious than the preceding species, it is also 

 larger, darker in colour, and has more prominent 

 feet, &c. ; there are fifteen pairs of scales ; the tentacles 



are ringed with black ; the upper bristles are slightly 

 bent near the minutely serrated end, the lower ones 

 have the blade cut into two teeth at the end, and are 

 armed with spinous denticles on the convex side. 

 P. scolopcndfina is about four inches long, and is 

 flattened in shape ; there are pairs of small, decid- 

 uous scales only on the fifteen anterior segments, the 

 remaining divisions, although dotted with tubercles, 

 being quite naked ; the antennae, palpi, &c., are only 

 slightly thickened below the point, and are covered 

 with fine hairs ; there are only two eyes ; the upper 

 bristles are blunt and roughish on one side, the lower 

 bristles are larger, two of them having a large trian- 

 gular lance-head (this is very characteristic), and the 

 other one being like a hedge-knife with two sharp 

 teeth at the end of the minutely-toothed blade. 



The genus Aphrodita embraces forms that may be 

 regarded as among the wonders of the animal crea- 

 tion. Here we have the sea-mouse which frequents 

 the mud and sand of the deep sea bottom, and is 

 frequently hurled ashore by the tide. What a won- 

 drous structure of organism, what a brilliant glow of 

 colour ! What an exquisite combination of green 

 and gold and reddish-brown, all supremely lustrous 

 and beautiful ! Whence is the origin of all this 

 splendour, of what utility is it, what function does it 

 discharge in the life-economy of the animal ? It is a 

 sluggish creature, it crawls by the apparently rhyth- 

 mical, alternate sheathing and projecting of its hard 

 stiff bristles ; but its life-energy, its individual force 

 must be remarkaljly powerful, its affluence of beauty 

 must spring from and be sustained by animal or vital 

 energies pre-eminently vigorous and efficient. The 

 anatomy of this genus exhibits manifold features of 

 interest. The nerve chords are contiguous ; the 

 peritoneal fluid is very voluminous, and although it 

 is highly charged with oxygen, it contains but few 

 corpuscles, while the blood-proper is almost obsolete. 

 The scales on the back are supplied with numerous 

 muscles, and are coated with a layer of felt which is 

 permeable by the water, while the internal cavities 

 of the body are shut out by a membranous partition 

 from the spacious exterior enclosure beneath the 

 scales called the peritoneal chamber. The stomach 

 floats as it were in this chamber, and is a straight 

 tube with a series of lateral pouches invested with 

 functions similar to those of the preceding genus, and 

 there are segmental organs, which are branched 

 tubuli filled with the reproductive . products, and 

 having a renal function ; the proboscis has no or only 

 rudimentary teeth, but its orifice is encircled with a 

 fringe of filaments, each being a short stalk crowned 

 with a tuft of forked papilla;, the inner membrane is 

 highly vascular, and on the exterior of this fringe 

 there are four fleshy tul^crclcs. The feet are of two 

 kinds, squamiferous and cirrigerous, and are divided 

 into two branches. A. aculcata is from three to eight 

 inches long, and is profusely decorated on the back 

 and sides with a splendid raiment of green and gold, 



