48 Records of the Indian Museum. [Vol. XVI, 



I prefer in similar cases to follow the view of Cook, assuming 

 as type of the genus the first species ascribed to it b}' the author 

 of the genus; in my opinion, therefore, Mecisiocephalus, Newport 

 has M . ferrugineus as type species and cannot be included in this 

 family, which takes its name from another genus proposed by 

 Cook, viz Dicellophilus. 



On the characters for distinction of genera and species. 



In this family good characters for the distinction of the genera 

 are the form of the maxillary palps, the presence or absence of a 

 spine on the underside of the anterior sublateral region of the epicra- 

 nium, and the development of the subcoxae of the pregenital seg- 

 ment. I could not find any basis for the distinction of genera in the 

 form of the teeth of the pectinate laminae of the mandibles, nor in 

 the presence or absence of setae on the lateral parts of the labrum. 

 Such characters have been retained as of great importance in the 

 distinction of species, together with that of the relative length of 

 the head, the number and form of the teeth of the maxillipedes, 

 the form of the sternal furca, of the sternum and the number of 

 pori on the subcoxae of the pregenital segment. 



I note that the relative length of the epicranium has its value, 

 but not an absolute value, because it appears to me to be variable 

 in some degree and sometimes very variable on account of mutation 

 or aberration. I, therefore, think it is not to be considered of first 

 importance and cannot serve for the distinction of species, i[ not 

 observed in a good series of specimens. This view has been fol- 

 lowed by me invariably and a case I consider as an aberration is 

 briefly discussed in the description of Lamnonyx maxillaris. 



The colour also is very variable in the genus Lamnonyx and 

 has, therefore, not been used by me for the distinction of species or 

 of varieties. 



On geographicaIv distribution. 



The genera of Dicellophilinae known up to date are especially 

 distributed from Japan and China to New Guinea, Malaysia and 

 India. 



Western North America has two genera with three species and 

 Europe only one species, belonging to one of the North American 

 genera, viz. Dicellophilus. 



Tropical Africa has a species, L. insularis (lyUcas), which 

 extends to India, and in some places L. maxillaris (Gerv.), which 

 is actually tropocosmopolitan and has been introduced into the 

 Canary Is. and into Madeira, Paris and Hamburg. 



South America, if we exclude Tygarrup intermedius, Chamber- 

 lin, described as coming from British Guiana but collected in 

 pots of plants in Washington, has only the tropocosmopolitan 

 L. maxillaris. 



The centre of formation and distribution of genera and species 

 of Dicellophilinae has certainly been somewhere between Japan, 

 New Guinea and India. 



