CONUS CONE. 65 



LESSON XII. 



Teacher. If any one were now to speak to you 

 of a Conus, what idea would the name call up to 

 your mind ? 



Child. The name Conus would recall the idea 

 of a univalve shell, whose form is inversely co- 

 nical and turbinate ; the spire retuse ; whorls 

 spirally convoluted ; aperture linear, longitudinal, 

 entire, effuse at the hase ; columellar lip smooth, 

 having sometimes a few oblique rugose striae 

 towards its base. 



Teacher. All the shells before us possess 

 these qualities, or they would not be Cones : 

 but are they alike in all respects ? 



Child. No ; they differ very much in their 

 colours and patterns, and also in their size. 



Teacher. On account of this variety in the 

 shells possessing the same generic marks, the 

 different genera have been subdivided into species, 

 the characters of which are determined by the 

 circumstances of colour, markings, size, and the 



attended to in their composition, is fluency, and this will be 

 best promoted by allowing them to use their own expressions, 

 and follow their own arrangement of the subject. When 

 they have learnt to express themselves readily, they should 

 be taught to seek for appropriate language, and to correct the 

 inaccurate and inelegant expressions in their compositions. 

 They should also be instructed to consider their subject well, 

 before they begin to write, that they may arrange the matter 

 in the best order. 



