i 



THE ENTOMOLOGIST 



Vol. XLVL] AUGUST, 1913. [No. 603 



A SUMMARY OF THE PRESENT KNOWLEDGE 

 OF THE PROTURA. 



By C. B. Williams, B.A., F.E.S. 



The only publication at present on the Protura in English 

 is a rather short and popular article by Mr. R. S. Bagnall [1] ,* 

 in which he gives the first record of their occurrence in Britain. 

 The object of the present paper is to give more fully an account 

 of this order, in the hope of calling the attention of English 

 entomologists to the many interesting and unique characters 

 which they possess, and also to give some account of the 

 different views held on the much-debated question of their 

 systematic position. 



The Protura are a group of minute, wingless arthropods, 

 probably insects, the largest of which are not two millimetres in 

 length. The most notable feature on first examination is the 

 absence of antennae, which differentiates them immediately 

 from all known insects (except the almost structureless female 

 of the Strepsiptera) and, together with their lack of wings 

 and elongate general appearance, has doubtless long caused 

 them to be mistaken for larvae when, or if, they had been 

 seen. A pointed head, three pairs of rather long legs, and 

 a truncate many-segmented abdomen without cerci are also 

 characteristic features, while on closer examination minute 

 appendages may be made out on the ventral side of the first 

 three abdominal segments. 



The group was first described so short a time ago as 1907 by 

 Silvestri [18], from Italy, one species Acerentomon doderoi being 

 described. In the following year Berlese published two short 

 papers, the first [3] describing a new genus and four new 

 species, the second [4] describing three more species, and 

 giving some account of their internal structure. In 1909 

 appeared a short note by Borner [7, p. 125 footnote] ; descrip- 

 tions of a species from America by Silvestri [19] ; and then 

 Berlese's large monograph [5] which still remains by far the 



* The numbers in square brackets refer to the Bibliography at the end. 

 ENTOM. — AUGUST, 1913. S 



