I2 4 THE YOUNG NATURALIST. 



[July 



long as the wearer keeps out of holes, no trouble from damp is to be 

 feared. Mr. R — wore a pair of fishing stockings, reaching to the 

 middle, but as it took him half-an-hour to get inside of them, and re- 

 quired the assistance of a second person to pull him out, the advan- 

 tages of the outfit were reduced to a minimum. 



A splendid series of the two shells, Littorina nidis, var. sulcata, and 

 L. obtusata with the var. fabalis could be collected here in a few min- 

 utes, especially the latter, which is excessively common. -Then their 

 near ally, the Periwinkle, L. littcea, is almost, if not quite as abundant, 

 and it is worth while to take a couple of the finest specimens for the 

 purpose of examining the curiously long odontophore. During our 

 stay, we gave considerable attention to the gasteropod molluscs, and 

 made it a point to secure a slide of the lingual ribbon of all the com- 

 moner species. And here let us emphasize the utility of making pre- 

 parations of the entire organ. Fragmentary portions, useful though 

 they may be as affording a key to the dentition, can give the observer 

 no notion whatever of the actual extent of the ribbon. The size of the 

 animal is no criterion of the dimensions of its odontophore, and the 

 utmost incongruities in respect to this point are of repeated occurrence. 

 In Patella vulgata, the common Limpet, or "flitter," as the Manxmen 

 call it, the lingual ribbon oftentimes attains a length of three inches, 

 and makes a microscopic object of wonderful beauty. In some in- 

 stances, the odontophore is not very readily found, and in others it is 

 a matter of no small difficulty to free it from its attachments and 

 enveloping tissue. The animal may first be killed with hot water, and 

 if the shell be of the spiral pattern, it is well to carefully break it off 

 with a light hammer. In the case of molluscs having a retractile 

 probosis, the radula may be laid bare by inserting the point of a pair 

 of sharp dissecting scissors, and making a medio-dorsal slit. Some- 

 time it will be necessary to trace it along its entire length, cutting it 

 free as the dissection progresses, but as often as not (in Patella for 

 example) the ribbon may be drawn carefully out in its entirety. Or it 

 may be needful, as with the Nudibranchiata, to remove the buccal 

 mass, on the floor of which the odontophore will be found. And a 

 wonderfully efficacious piece of apparatus it is ; whether employed to 

 rasp and file a hole in the shell of another mollusc, that the unhappy 

 occupant may afford a meal for the industrious worker, or to tear t 

 fragments the tender algae upon which other species love to feed, 

 fulfils the condition of perfect fitness. 



