!l8 



HARDWICKE'S SCIENCE-GOSSIP. 



tip of the papilla, we see the aforesaid oval chamber 

 packed with numerous little whitish, elliptical or 

 kidney-shaped bodies, like so many haricot beans of 

 different shapes and sizes. They are on the move, 

 and behold ! from two narrow ducts or channels at 

 the extreme end of the papilla there emerge a series 

 of large round bags, each packed full with these 

 thread-cells (otiJu). These bags presently burst and 

 scatter their contents about the slide. Now watch 

 one of the largest of these bean-like bodies, and lo ! 

 a nipple projects from one end, and presently a long 

 stoutish thread shoots forth to a considerable distance 

 like the tail of a rocket. This thread is conspicuously 

 thickened at that portion of its length which is next 

 the cell for about the length of the latter, and at a 

 favourable glance of the light we can see a barb-like 

 appearance investing this stouter part. Careful and 

 prolonged observation reveals the fact, that this is 

 composed of a thickish band that clasps round the 

 thread for some distance, and is studded with projec- 

 ting sharp bristles, that impart to the organ a potent 

 irritating or stinging power. This thread is very 

 insinuating, and can penetrate thickish animal tissue, 

 infusing therein at the same time a fluid of a highly 

 venomous character. We now see how it may be 

 that when this beautiful sea-slug would be confronted 

 by the enemy, the latter in his advances would be 

 pretty sure to " catch a Tartar." 



There are upwards of forty British species of Eolis, 

 some of which have the papilLx depressed and over- 

 lapping, some present them in a number of separate 

 tufts or clusters, some in rows arranged crosswise on 

 the body, and a very few have a single row of them 

 on each side. Of these various species Eolis coroitata 

 is in many localities one of the commonest. Its body 

 is about one inch long, and lanceolate in shape ; the 

 papilloc are crimson blotched with blue, and ar- 

 ranged in six or seven clusters each containing twenty 

 to thirty or less; the dorsal tentacles are fringed, 

 and the oral ones are long and slender ; the tongue 

 has about twenty-three large, strong, comb-like teeth, 

 each cut into sixteen toothlets. Eolis Driimniondi 

 is about one and a half inches long when fully de- 

 veloped, with the front angles of the foot much elon- 

 gated ; the papillae are long, reddish-brown with 

 opaque-white tips, and set in four to six clusters ; the 

 dorsal tentacles have twenty to thirty rings, and the 

 oral ones are very long, slender and simple ; the 

 tongue of the species presents sixteen amber or green- 

 tinted teeth, each bearing nine denticles on each side. 

 Eolis papulosa may be regarded as the non-pareil of 

 its interesting and beautiful genus ; it sometimes 

 measures three inches in length, is broad and stout, 

 but tapers gradually to the rear, and is of a brown- 

 puq^le colour dappled with while, pink, brown, &c., 

 an exquisite organism ; the papillae are marshalled 

 in from six to twenty distinct rows, each row com- 

 posed of about four to six filaments ; the dorsal and 

 the oral tentacles are short, stout, and without rings ; 



the tongue is thick, fleshy, and dark-coloured, and 

 bristles with thirty plates each cut into about 

 forty denticles ; the liver is very highly developed, 

 the central channel of the papillae giving off on all 

 sides variously sized and irregularly shaped sacs, 

 which are crammed with little compound bags or 

 follicles ; the species sojourns between tide-marks on 

 a rocky or shingly coast, where the bottom is a little 

 muddy. Eolis tricolor has a yellowish body with 

 orange, violet, and yellow papillae, which are large, 

 flesh-shaped, and pellucid, and disposed in about 

 thirteen rows of from three to five in each ; the dorsal 

 tentacles are smooth, stout, and fawn-coloured, and 

 the oral ones slender. Another species of this family 

 is IkrmcLa bifida, which is tolerably numerous and 

 common. It has a long slim body, and sports a 

 yellowish integument with two reddish lines at the 

 base of the papillae ; the latter organs are arranged 

 tumultuously adown both sides of the back, and they 

 are large and stout, and of a transparent red colour 

 with a deep red central vessel or liver ; the 

 tentacles are short and folded lengthwise ; there are 

 no jaws, and the animal, which is extremely agile, 

 may be regarded as a link between the Eolidae and 

 the Elysiadae ; its tongue has forty-nine rows of 

 curiously- shaped teeth. 



And now we come to certain genera which may 

 be regarded as forming a separate section or sub- 

 family of Eolidae, and which, inasmuch as they differ 

 in their external characters from the aforesaid genera, 

 have been relegated to another family by certain 

 adepts in classification. These forms have retractile 

 tentacles sheathed below, the lingual membrane is 

 usually furnished with a series of lateral teeth, &c., 

 and their general aspect may be regarded as some- 

 thing intermediate between the Eolidae and its nearest 

 allied family the Tritonidte. Among this sub-group 

 there occur a few creatures which are tolerably 

 common, and are amongst the loveliest inhabitants 

 of the ocean. The parent of so many forms of 

 strange and fairy loveliness hides not within its abysses 

 a more exquisite organism than what is known to 

 science as Dendronotus arborescais. Its back bristles 

 with a perfect forest of gills, or rather papillae, and 

 a tuft of branched appendages projects in front of the 

 head ; the dorsal tentacles have somewhat the shape 

 of a penny fly-wheel used by children ; the body is 

 beautifully painted and decked with various tints and 

 shades of crimson,'reddish-brown, yellow, and opaque - 

 white beautiful to behold ; the tongue is an organ of 

 fair proportion, it bears a large broad serrated tooth, 

 flanked on either side by ten oblong, also serrated, 

 teeth ; this creature has the faculty of emitting audible 

 sounds ; it frequents seaweeds and corallines from low- 

 water to about fifty fathoms depth, and, taken all in 

 all, it is an exquisitely modelled and painted organism, 

 the very non-pareil of British Nudibranchs. Meliboea 

 coronata is another beautiful species of the same sub- 

 family. It is about half an inch long, and bears on 



