270 



were employed for crushing the stones into 

 the earth, visitors covered them with dirt, 

 and in a short time, not a specimen was to 

 be obtained. The best time to visit the spot 

 was during, or immediately after a shower, 

 when the limestone was wet. 



Fossilized remains are usually kept in 

 cabinets, similar in construction to those 

 used by Entomologists. The fossils are 

 arranged in columns, with the name of the 

 class under which each row is grouped, at 

 the head of the column. Thus, for example, 

 when we open a drawer, we see at the top of 

 the fifth column the name : 



Somewhere in the same row will be a shell 

 labelled : 



EUOMPHALUS pentangulatus. 

 CARB. LIMESTE. 

 DERBYSHIRE. 



Then follow the other classes in their order 

 of arrangement. Some shells, such as Tere- 

 bratula and Rhynconella are very apt to roll 

 about. To prevent this, small shallow card- 

 board boxes are made, slightly larger than 

 the specimen, which is deposited upon a layer 

 of lint placed on the bottom. Very large 

 fossils should not be kept in a cabinet, being 

 apt to make the drawers heavy, and often 

 causing ths bottoms to split, and fall out. 



In conclusion, I must not omit to mention 

 the unavoidable yet constant occurrence of 

 scientific names. I have never been accus- 

 tomed to use common English names, nor am 

 I aware that there are many such terms in 

 use. 'Tis true that Belemnites are called by 

 the quarrymen "thunderbolts," and Terebra- 

 tulce are designated by geologists as "lamp- 

 shells," but such names are apt to be mis- 

 leading. The Terebratula resembles one of 

 the ancient lamps used by the Romans, and 

 hence its specific title ; but I am sure that no 

 one would think of saying that he had a col- 

 lection of "thunderbolts." 



If the student will only accustom himself to 



use scientific names from the very beginning, 

 no matter what the science may be, he will 

 find them much more advantageous than if 

 he adopted the plain English terms. 



CONCHOLOGY. 



LAND AND FRESH-WATER SHELLS. 

 By Mr. H. T. Robson, Stockton-on-Tees. 



Conchology is the science which teaches us 

 how to classify the various shells, and arrange 

 them in their respective families, genera, and 

 species, as well as to understand the mode of 

 formation, characteristics, and life history of 

 each. 



By far the greater number of shells are to 

 be found in the sea, and these must remain 

 for notice on some future occasion, those only 

 claiming present attention which are to be 

 found on land, or in fresh-water ; but before 

 beginning to speak of any particular class, 

 there are generalities to consider which refer 

 to all alike. 



Shells are the coverings of soft-bodied 

 animals called Mollusca (from the Latin Mollis, 

 soft), they have soft fleshy bodies without any 

 internal skeleton, the majority of them are 

 protected by an external shell, but some are 

 entirely naked ; they have all more or less 

 the power of contracting and extending their 

 bodies, or portions of them, and they are thus 

 enabled to retreat into or emerge from their 

 shells, to move about from place to place in 

 search of food, or otherwise perform such 

 motions as the necessities of their nature 

 demand. 



They may be distinguished from worms 

 and insects by the latter being divided into 

 rings or segments, while the mollusca are not. 

 They differ from the Crustacea (crabs, lobsters, 

 &c.) not only in the jointed limbs which these 

 possess, but also in the nature and mode of 

 growth of the shell. They do not include the 

 Echinida (sea urchins, &c.) which have cal- 

 careous shells, composed of a number of 

 plates placed edge to edge, and covered with 



