!) 



The first two families contain species 

 frequently remarkably elaborate in the 

 development of the tentacular proc- 

 esses ujion the back and sides, often 

 of most brilliant and varied coloration, 

 while the substance of their bodies is 

 but a trifling- degree harder than that of 

 the jelly-fishes; the various tissues of 

 the body being so transparent and deli- 

 cate that the beating of the heart and 

 the digestive processes are discernible. 



1 2 



NUDIBRANCHIATE MOLLUSKS. 



These remarkable creatures, many of 

 them of marvelous beauty, are found in 

 all parts of the oceanic waters, from the 

 Arctic to the Equatorial seas; probably 

 thousands of species exist as yet unde- 

 scribed. As but few of the naked- 

 gilled mollusks are of a substance suffi- 

 ciently solid to admit of preservation in 

 alcohol, they are seldom seen in collec- 

 tions. They may be detected at lowest, 

 water -mark on the under side of rocks, 

 appearing to the uneducated observer 

 as nothing more than a highly colored 



bit of mucus or slime, for the reason 

 that being exceedingly timid, when dis- 

 turbed they draw their bodies into an 

 almost shapeless lump. 



Figures 1 and 2 represent two spe- 

 cies of California Nudibranchiate (or 

 naked -gilled) Mollusks, magnified, be- 

 ing twice as long and twice as wide a^ 

 the living specimens wei'e from which 

 the drawings were made; both belong- 

 ing to the group of Triopa. The first 

 (Fig. 1) is Laleribranchceia /estiva, so 

 named because the branchsea or gills 

 are on the side of the body and oppo- 

 site each other; the body is of a trans- 

 parent cream color, and the festooned 

 or loojDed lines on the back are of an 

 oj)aque chalky whiteness, while the sub- 

 stance of the bodies in both of the 

 forms figured is nearly as soft as jelly. 



The largest of the two figures is IVi- 

 opa Carpenteri, named for Dr. P. P. 

 Carpenter, a distinguished naturalist, 

 well known among scientific men for 

 his laborious and thorough investiga- 

 tions in the natural history of the west 

 coast of North America. This animal 

 is exceedingly pretty when alive and 

 examined with a magnifier; the upper 

 part of the club-shaped tentacles near 

 the head, and the edges of the gill- 

 plumes which resemble delicate fern- 

 leaves, as well as the ends of the short 

 projecting processes around the edge of 

 the body, are tipj^ed with a brilliant 

 orange, and the body, which is of a 

 translucent whiteness, is covered with 

 fine pimples {papilla}) qi orange. Both 

 L. /estiva and T. Carpenteri were found 

 on the under side of large granite 

 bowlders near the light -house at Point 

 Pinos, Monterey. When visiting the 

 sea-shore, it will well repay the trouble 

 to turn over some of the bowlders, for 

 Nature hides many such beautiful forms 

 as are above described, in just such out- 

 of-the-way places. 



