2 BEITISH CICADiE. 



Plafymetophis, "et plusienrs genres encore mal definis," 

 such as Deltocephahis, &c. 



The ocelli of Paramcsus, he remarks, are to be 

 found on the vertex, but they do not touch the head- 

 border, and are not placed on the ideal line traced 

 from eye to eye, and passing near to the summit of 

 the head. 



I may remark that if the ocelli could in all cases be 

 seen, their position on the head would doubtless 

 furnish very useful classificatory characters. But, so 

 far as my experience goes, in many cases they fail to 

 show themselves, and in other cases they have their 

 representatives as mere spots of pigment; quite unlike 

 the definite lens-like bodies on the crowns of TeUigonia 

 or Cicadetta. 



The limbus, appendix, or membranous fold on the 

 elytron is, by its presence or otherwise, a good character 

 for species, but, as a rule, not so much so for genera. 

 The genus Tartessus has not yet found a representative 

 in Britain. It has the peculiarity of showing this 

 limbus far over the point of the elytron, encircliug 

 four, instead of three, of the apical cellules. 



The characters of the head and the abdominal parts 

 of the males of Ewpelix are so marked, that there are 

 good reasons for erecting the species into a group by 

 themselves, as has been suggested by Sahlberg. 



As we have, however, only one undoubted English 

 species, I have not thought it necessary to cut it out of 

 the Acocephalidge. 



In a general way it may be said that the male 

 pygofer of the Acocephalidse is on a type of two styles, 

 two oblong plates, two genital valves, and a penis. 

 Above these is placed the cauda or anal tube; which 

 appendage, there is reason to believe, is perforated, 

 and ends with a lougitudinal excretory slit. 



The female pygofer contains two thin toothed saws, 

 and two laminated rasp-like plates, all of which parts 

 are enclosed in the large exterior valves to be seen on 

 the under side, and formed by the chitinous plate or 

 conical folding of the pygofer. 



