54 Mr. W. L. Distant on 



duction were supplied within the phylum of these animals 

 themselves and their peculiar circumstances. In the same 

 way, too, this point of view may well be adopted for the 

 Medusan Strobila also, no matter whether we would derive it 

 with Glaus * from the gemmation of stolons or nut. 



We thus arrive at the final result, that the customary idea 

 of the intimate relationship between fission and gemmation 

 has no justification in facts, but rather that the separation of 

 the asexual reproductions of the Metazoa possesses not only a 

 notional meaning, but also a real foundation. 



The cases of asexual reproduction in the various animal 

 phyla have proceeded independently of one another from con- 

 ditions existing within these phyla, so that that which, it may 

 be, can be rendered probable for a single case of reproduction 

 or for a congeries of similar cases, includes no binding force 

 for other instances of multiplication by fission or gemmation. 



It will be the task of future investigation, in determinnig 

 the originating causes which have decided the character of 

 each form of reproduction belonging to the present category, 

 to separate chaff from wheat, so to speak, i. e. to eliminate 

 from the series of propagations those modes of multiplication 

 which represent mere augmentations. Merit is due to von 

 Kennel for having emphatically drawn attention to this 

 important difference f. 



VII. — On some M?i£?esm^ec? Cicadidte, with Synonymical 

 Notes. By W. L. Distant. 



It has been urged, and with some reason, that descriptive 

 papers should, where possible, be confined to the diagnoses of 

 members of some particular zoological region ; and if this 

 course could always be pursued the convenience it would afford 

 to purely faunistic workers would doubtless be great. But the 

 formulation of rules and theories is often a very special gift of 

 a very few, and is sometimes in an inverse ratio to possibili- 

 ties and experience. There is, however, a course which will 

 enable the descriptions of widely distributed insects to be 

 faunistically apprehended, and that is by geographically 

 tabulating the species described in some manner similar to 

 the following, which applies to the present paper. 



* C. Claus, ' Untersuchungen liber die Organisation und Eutwicklung 

 der jNIedusen,' Leipzig, 1883, p. 18. 

 t J. V. Kennel, ' Ueber Tbeilung und Knospung der Tiiiere,' p. 8. 



