278 POPULAR COKCHOLOGY. 



GUIDE 



TO 



THE USE OF THE TABLES. 



The young student will soon ascertain the generic name 

 of any shell by adhering to the following method : — 

 We will suppose an oyster to be a shell under examin- 

 ation. At one glance it will be found to be a Bivalve. 

 The first table must, therefore, be consulted, which is 

 found to be divided into three orders, each of which 

 must be examined. The first has no ligament, but a 

 pedicle to attach the shell to other substances. The 

 oyster having a ligament (if the specimen be perfect), the 

 description of the next order must be looked at ; but the 

 two muscular impressions at once determine that the 

 oyster does not belong to it. The specimen, therefore, 

 must be placed amongst the Monomyaria, which is divided 

 into two parts : the first has the ligament lengthened, 

 which is not the case with the oyster, for it is thick and 

 short. It may, therefore, be concluded that the shell 

 belongs to the second division, and to one of its two 

 families. The Pectenidae are distinguished by the shells 

 being solid, eared, and often ribbed. The oyster does not 

 resemble this description, and therefore must be of the 

 Ostreidse family, for it is foliaceous. When the family is 

 ascertained, the generic name is found by turning to the 

 description of the former in the body of the work ; and 

 the account of each genus, with the assistance of the 

 drawing, will enable the student to determine that the 



