82 ENTOMOLOGISK TIDSKRIFT 1894. 



within the mangrove forest and preserved in rum. Asking him^ 

 if he, when the rat was captured, not had seen any yellowisli 

 Insects springing about itf he answered that such were very nume- 

 rous, but probably lost during the bringing home of the animal, 

 some of them, however, perhaps remained and were then to be 

 found in the rum containing the rat, a supposition which proved 

 to be right, because I found on the bottom of the jar 7 — 8 spe- 

 cimens.» 



This letter gives very interesting informations about the occur- 

 rence and habits of the Heminienis ; concerning the Rodents 

 collected by Mr. Sjöstedt in Kamerun and indicated in the letter 

 I may perhaps refer the reader to Tvcho Tullberg: Ueber einige 

 Muriden aus Kamerum (Nova Acta Reg. Soc. Sc. Ups. Ser. 

 III, 1893). 



What the Heminienis feeds upon seems to me, however, to 

 be rather puzzling. On account of the structure of the mouth 

 we are able to say with considerable certainty, that it does not 

 nourish itself by biting apertures in the skin of the host and 

 sucking blood; it is more probable that it is feeding as most part 

 of the MallopJiaga, but its mouth-parts are, however, very different 

 from those found within this large group. Perhaps the Hemi- 

 merJis feeds upon other small parasites on the Cricetoinys, and, 

 according to the shape of the mouth-organs, this supposition does 

 not seem quite improbable. The proventriculus does not possess 

 the rows of chitin-tacks, found f. inst. in the Blatthia and 

 Gyyllodea. 



V. Literature on the subject. 



Saussure writes (op. cit. p. 5): »En 1871, Francis Walker 

 a indiqué plutôt que décrit, sous le nom de Heinimeriis, un genre 

 d'insectes aptères, qu'il classa dans l'ordre des Orthoptères, famille 

 des Gryllides, tribu des Gryllotalpiens (Catalogue of the species 

 of Dermaptera, Saltatoria, etc. of the British Museum, t. V, 1871, 

 Supplém. page 2).» This statement must be sufficient as to the 

 description of Walker, as I have not seen the quoted work. — 

 The treatise of Saussure, the capital work on this animal, con- 

 tains c. 22 pages in 4to and i plate, and is based on the exa- 



18 



