1890.] E. T. Atkinson— Ca^aZo^Me 0/ the Family Dytiscidae. 12/ 



I. — Catalogue of the Insecta of the Oriental Region. No. 4; Order 



Coleoptera, Family Dytiscidae. — By E. T. Atkinson, B. A. 



Pr. D, Sharp's monograph entitled * On aquatic carnivorous Coleoptera 

 or DytiscidsB ' (Scientific Transactions, Royal Dublin Society, (2s.) ii, 

 1881-2) renders the preparation of the * Catalogue of the Dytiscidse,' 

 a comparatively easy task. Mr. Sharp's elaborate work is prefaced by a 

 general description of the position of the family, its extent, and some 

 criticisms on the taxonomy ; whilst another chapter is devoted to a de- 

 tailed description of the structure. In the prefatory chapter, Mr. Sharp 

 remarks : — *' We possess already in the Munich Catalogue of Coleoptera 

 a work in which a large proportion of synonyms are well recorded, and 

 I have considered the existence of this valuable production sufficient 

 reason for omitting the synonymy already recorded therein, and have 

 contented myself with citing in the alphabetical index of this work such 

 names as are necessary to establish a harmony between it and the cata- 

 logue in question. For a similar reason it forms no part of my plan to 

 give a history of the previous and present condition of the taxonomy of 

 the family, nor a list of all the writers who have described species belonging 

 to it, both of these can be gathered from the Munich Catalogue." 



Following a like procedure, I give those species recorded in the Munich 

 Catalogue with their synonymy and a reference to the place in which 

 they are noticed in Mr. Sharp's work, and for those described since 1868, 

 the synonymy admitted by him. Up to the year 1882, Dr. Sharp's 

 monograph and the Munich Catalogue may be considered safe and sufficient 

 guides to the study of this family. In Mr, Sharp's work, there is some 

 departure from the ordinary practice in the record of species, which are 

 given under the genus and specific name of the origiual describer, whilst 

 the genera under which they are placed have neither author's names nor 

 references. It is difficult therefore to ascertain whether the genus of 

 Dr. Sharp is the same as the genus of the original describer, or even, 

 in any strict sense, belongs to it. Therefore the references to the genera in 

 the following Catalogue must be understood to be subject to the modifi. 

 cations introduced by Dr. Sharp in his diagnoses. It would be impossible 

 for me to distinguish accurately between the various phases which succes- 

 sive emendations and sub-divisions have given rise to in a genus, nor would 

 this be the proper place to attempt such a task. Broadly, Dr. Sharp 

 divides the Vytiscidoi into two main groups, Dytisci Fragmentati (p. 963) 



