TROcnus. 33 



and simple in fact it is to one, who, by attentive studj'', has 

 become familiarized with the meaning of the terms. To one also 

 who is acquainted with the Greek and Latin tongues, they will 

 be sufficiently plain, although he has never seen them applied 

 before, for they are all derived from those dead languages, as 

 they are called, and so convey their own meaning to every 

 educated naturalist, no matter of what nation he may be; and 

 hence their chief value. It is not necessary for our readers 

 to trouble themselves about the meaning of such terms at 

 present; by and by it will be necessary for them to do so, 

 if they wish to prosecute the study of any natural science. 



Eut about the Impei'-ial Trochus, with its "orbicularly 

 conical" shell — that term we may explain as round and cone- 

 like; a reference to Fig. 4, Plate IV, will show what is 

 meant by this more clearly than words can, and likewise ex- 

 hibit the beautiful markings of this species, with its ground 

 tint of rich violet brown. This beauty is often obscured by 

 calcarious incrustations and marine plants, showing that the 

 mollusk is sluggish in its habits — a slothful creature. So it is 

 with human beings, sloth covers and hides the good qualities 

 and virtues with an overgrowth at all times difficult to 

 remove, and oftentimes destructive of all that is' fair and good 

 in the character. — Children, be not slothful! The Obelisk 

 Trochus, (J', obeliscus,) is a rare white and green shell, some- 

 times seen in collections; it is of a conico-pyramidal form, not 

 remarkable for beauty, and is a native of the Indian seas. 



Mr. Gosse speaks of the Tops and Winkles as among the 

 most useful inhabitants of the Aquarium; they mow down 

 ^ with their rasping tongues the thick growth of Confer vte 

 which would otherwise spread like a green curtain over the 

 glass walls of the tank, and obstruct the view of its inhabi- 

 tants. Here is this author's description of the beautiful piece 

 of mechanism by which this work is effected: — ''The appearance 

 and position of the organ would surprise any one who searched 

 for it for the first time, and as it is easily found, and as 

 Periwinkles are no rarities, let me commend it to your ex- 

 amination. The easiest mode of extracting it, supposing you 

 are looking for it alone, is to slit tlie thick muzzle between 

 the two tentacles, when the point of a needle will catch and 

 draw out what looks like a slender white thread, two inches 



