HARDWICKKS SCIENCE-GOSSIP. 



195 



artificers of spicula. D. pilosa seems to be rather 

 more active on its foot than its congeners (its pedal 

 i;angha are. quite distinct), it crawls with greater 

 facility and velocity. Its jaws are curiously con- 

 structed. They are furnished with a collar divided 

 into two parts, broad below and tapering to a point 

 above, and thickly studded with two-cleft spines, with 

 two small horny triangular plates below. The tongue 

 somewhat resembles that of some of the Eolidse ; it 

 lias twenty-seven rows of eight teeth each (four on 

 each side), the three outer ones being mere rudiments, 

 while the inner ones are very large and broad below 

 with a lateral arch, the apex being much extended and 

 curv.ed, with a row of minute toothlets like a tiny 

 balustrade flanking the side. This species ranges 

 in habitat from about mid-tide level to the coralline 

 zone, or to about fifty fathoms depth. 



Fig. 134. — Sea Slug (Eolis coroiiata). 



There are various other species of British Doridse, 

 a few of which, although comparatively rare and not 

 specially partial to the life ashore, are still commoner 

 than their immediate congeners, and on this account 

 we shall merely indicate briefly their more salient 

 specific characters. And it may be premised that in 

 these forms we observe two principal features which 

 distinguish them from the genera already delineated, 

 viz., (i) the cloak gradually becomes smaller and 

 more "cutty," and (2) the gills are less developed, 

 and their function becomes shared or more or less 

 usurped by a series of appendages which now begin 

 to sprout forth from the sides of the body. Thus 

 in Goniodoris nodosa, the cloak, occupying only the 

 foremost two-thirds of the back, exposes the head 

 and foot, it has a curved edge, and a central elevation 

 with a row of minute tubercles or wart-like appendages 

 on each side ; this species has thirteen branchial 

 plumes smaller than in Doris, its length is about one 

 inch, and it is of a white colour tinged with yellow 

 and pink, and dappled with white spots. Triopa 

 flaviger has been described as like a little lump of 

 whitish jelly dappled with orange-yellow, not bigger 

 than half a split pea, clinging close to the under side 

 of a stone. It is of an oblong shape with about seven 

 well-developed appendages on each side of the 

 smallish cloak, the branchial being reduced to 

 three in number ; tentacles are club-shaped organs in 

 front of the head and retractile within sheaths, the 

 tongue has about twelve curved denticles on each side, 

 the outer two being longer than the rest, and the 

 skin is charged with cross-shaped and three-edged 



spicula, Polycfra qnadrUhieata is a third species ; 

 it is widely distributed, and therefore very variable, 

 its gills, which are seven to nine in number, are 

 conspicuously assisted in their function by a large 

 appendage on each side, the cloak is smaller than in 

 either of the two preceding species ; the body is 

 nearly one incli long, lanceolate, convex, smooth, and 

 of a white colour dappled with golden yellow, and 

 there are four to six awl-shaped processes on the 

 head which are tipped with yellow ; there are few 

 spicula in the body, and the creature is very active, 

 with a predilection for swimming back downwards 

 at the top of the water ; the tongue has fifteen rows 

 of twelve teeth in each tier. 



Occasionally, when fumbling about amongst the 

 small loose stones scattered near the water's edge, 

 we turn up one, whereon there appears beneath a 

 curious, irregular, transparent, yet coloured, filamen- 

 tous, flabby body. It is not much larger than a pea, 

 and seems curled up, or so packed and bundled "all 

 of a heap," as to elude observation ; for surely a 

 superficial glance would fail to discover anything 

 peculiar. However, on carefully removing this 

 snack of painted jelly, and placing it in a vase of 

 sea-water, one of the most beautiful little animals in 

 creation immediately "pulls itself together," or rather 

 unfolds to complete view. There is a waving move- 

 ment of the body, and instantly dense clusters and 

 tufts of dark-red striped filaments (papilla") quiver 

 and disentangle themselves, and unfold like the 

 petals of a fairy flower in the pantomime. Snatched 

 from the dull dark rock, grovelling amid mud and 

 slime, its colours and tints seem invested with a 

 fairy loveliness. Tiny as the organism is, its painting 

 is exceedingly beautiful, and its movements very 

 graceful, for it is boneless, so that no clumsy joint 

 interferes to check the free suppleness of action. 

 Seductively beautiful as it is, however, let every 

 minor creature beware of its proximity ; for there 

 lurks deadly danger in its lines, poison in its touch, 

 utter ruin in its very approach. The tip's of the 

 exquisite filaments that wave and quiver so gracefully 

 over its back, constitute an armoury of poisoned 

 darts, a very battery of mitrailleuses ready charged to 

 hurl thousands of death-winged missiles upon the 

 foe. This beauteous animal is a species of JSolis, the 

 type of the family Eolidse, a group of Nudibranchs 

 which is distinguished from the Dorida; by the pre- 

 sence of the following important characters : — There 

 are no special gills, nor any characters essential to a 

 true gill (aeration being performed by the whole 

 surface of the body) ; the stomach and liver extend 

 and branch out into a series of lengthened warts 

 (papillae), which are situated on the sides of the back ; 

 there are no special cloak and no spicula in the skin ; 

 the systemic blood-circulation is uncomplicated ; the 

 tongue is usually ^narrow, with a single series of large 

 teeth ; and there is a stinging or poisoning apparatus. 

 ( To be continued.) 



K 2 



