1893.] IIB. O. THOMAS 0:S THE WOKD " TXPE." 241 



1. Suggestions for the more definite use of tlie word 

 " Type ■" and its compounds, as denoting Specimens of 

 a greater or less degree of Authenticity. By Oldfield 

 Thomas, F.Z.S. 



[Eeceived February 14, 1893.] 



As systematic zoology becomes more and more exact and detailed, 

 the great value of the actual specimens to which specific names 

 have been applied, i. e. the " types," has been more and more 

 appreciated, but at the same time the word itself has been 

 applied by different authors so loosely and to specimens of such 

 very varied degrees of authenticity, that it seems as though an 

 exact definition of the term were somewhat of a desideratum, and 

 that at the same time it would be of great convenience to have by 

 means of compounds of the word "type "a set of names each applying 

 definitely to some particular class of sp3cimens. The word " type " 

 itself when first introduced was meant to refer to the particular speci- 

 men (in the singular) originally described, but it soon was naturally 

 applied to any individual of the original series, if more than one 

 specimen was examined by the describer. In this there was little 

 cause for confusion, but more recently it has been applied to any 

 individual from the collection of the original author, obtained 

 no matter how much later, and often not even determined by him as 

 belonging to his species. Of late a still further cause of confusion 

 has been introduced by certain authors who, obtaining specimens 

 from the typical locality, ha^ e spoken of them as " typical speci- 

 mens," a method of reference which, although due to a praise- 

 worthy regard for geographical exactness, is yet certainly liable to 

 give rise to inconvenience and confusion. 



But it will be readily admitted that these various classes of 

 specimens have each a certain value in relation to their respective 

 species, and, as the best means of obAaating the confusion above 

 referred to, it appears advisable that they should have definite 

 names showing their gi-eater or less degree of closeness to the true 

 original type. 



Already, as a step towards this end, the word " co-type " has 

 been introduced ^ for any specimen which was one of several 

 forming the basis of the original description ; but, like " type," it 

 has become loosely and vaguely used for different sorts and classes 

 of specimens, and equally needs definition and pinning down to 

 one particular class, for which alone it should be used. 



So far as regards their original material, species may be described 

 in one or other of the three following ways : — 

 I. On a single specimen, no others being seen. 



II. On two or more specimens, no one of them being selected as 

 the " type." 

 ITT. On a specimen selected out of a series of two or more, and 

 specially mentioned at the time as the " type." 



* I believe in the first case by my colleague Mr. C. O. Waterhouse. 



