346 



ARACHNOIDEA, 



CASE authorities for various names of mite-galls, whose papers, however, 

 we have not succeeded in procuring. 



Phytoptus. Copied from figure by Low. 



Head of Phytoptus. Enlarged from figure by Dr. Low. 



The reader may probably now ask what inference he is to draw 

 as to the affinities and nature of Phytopti from the facts above 

 mentioned. We have seen four conclusions drawn from their 

 observation by respective authors. Duges has suggested that they 

 are the young forms of a species of Tetranychus. Scheuten, that 

 they are the young of species of Gamasi. Latreille thought they 

 belonged to the Sarcoptidse ; and Dujardin, that they were a special 

 tribe by themselves. Let us take lach of these alternatives by 

 itself, and see what is to be said for and against it. Duges sup- 

 ported his notion that they might be the young of Tetranychi, 

 first, on the ground that the conical sucking apparatus is flanked 

 by two large short appendiculated (finger and thumb), palpi 



