60 MEMOIR OF RAY. 



iderable length, particularly those of the butterflies, 

 but their value is greatly diminished by the difficulty 

 in determining, owing to the want of plates and pre- 

 cise characters, to what particular species they were 

 designed to apply. Prefixed to the work there is 

 a systematic arrangement of insects, which was at 

 first published by itself under the title of Methodus 

 Insectorum. He divides insects, including under that 

 name intestinal vermes, earth-.worms, and leeches, 

 into two primary sections : those wnicn undergo 

 transformation, and tnose which do not change their 

 form. The orders are variously characterized by 

 the want or presence of feet, place of abode, struc- 

 ture of the wings, tbrm of the caterpillar, &c. The 

 following is a tabular view of this arrangement from 

 Kirby and Spence's Introduction, which these ad- 

 mirable authors have compressed into as small a 

 space as possible, by using the Linnaean terms for 

 metamorphoses, and reducing Kay's tribes of Orthop- 

 terv, Hemiptera, and Ne.uroptera* to their modern 

 denominations. 



