198 ENTOMOLOGICAL NEWS. [June,' 05 



No. 38. The type of a species belongs to one of the fol- 

 lowing categories : 



(i) Type (described from a unique specimen or from a single 

 specimen selected from a series). 



(2) Type (= type $ -f- type $ described from a single speci- 

 men of each sex). 



(3) Co-types (described from more than one specimen, no 

 single one being selected as the type. The type ^ the sum of 

 the co-types). 



No. 39. Each of the remaining specimens of a series from 

 which the type was selected is called a Paratype. 



A specimen subsequently named by the author after com- 

 parison with the type, is called a Metatype. 



A specimen named by another than the author, after com- 

 parison with the tvpe, is called a Homotype. 



A specimen collected in the exact locality whence the type 

 was obtained is called a Topotype. 



' ' [We have added the term Homotype to those proposed by 

 Mr. Oldfield Thomas (Pr. Z. Soc. Lond., 1893, 241-2, and 

 have slightly restricted the original definition of Metatype to 

 the exclusion of its necessarily being topotypical] . ' ' 



It is evident from these rules that the ' ' court of last resort ' ' 

 above mentioned must consist only of the classes defined under 

 Rule 38, and that insects falling in any of the classes defined 

 under Rule 39 are of less value. In fact a Topotype has no 

 actual type standing whatever, as an insect from "the exact 

 locality whence the type was obtained " may have been identi- 

 fied by a poor description, and not having been compared with 

 the type itself may possibly even be an entirely different spec- 

 ies ! 



A Homotype, to have its full value, should always bear on 

 its " Homotype " label the name of the person making the com- 

 parison, for the personal equation in such cases is a factor 

 which cannot always be safely neglected. 



In spite of these facts, Paratypes, Metatypes and Homotypes 

 are certainly more reliably named than insects identified by 

 descriptions only, and their presence in a collection should 

 make that collection far more valuable and trustworthy than 

 would otherwise be the case. 



