638 



SCONCE. 



[N. S. Vol. V. No. 121, 



may be the only example of a species 

 known at the time of original publication. 

 A holotype, therefore, is always a single in- 

 dividual, but may embrace one or jnore 

 parts, as the skin, skeleton or other portions. 

 When a holotype is selected, but other 

 specimens are also described, the latter 

 must be known as paratypes. When no 

 holotype is selected, and more than one 

 specimen is described, all become cotypes. 

 Therefore, the original material of any 

 species cannot include a holotype and co- 

 types, but may include a holotype and 

 paratypes, or all may be cotypes. 



In cases where a holotype is selected, 

 but no description or designation is given 

 to distinguish it from the associated ma- 

 terial, the holotype practically does not 

 exist. 



In cases where a holotype has been 

 selected, but the diagnosis is found to 

 contain more than one species, the re- 

 maining material will always constitute 

 the paratypes. These will not neces- 

 sarily remain as such under another 

 name, but will always be the paratypes of 

 the new species as interpreted by its author. 



The author of a new species having failed 

 to select a holotype, no subsequent author 

 can do this for him. No just law is retro- 

 active. However, there are two exceptions 

 which appear not to violate this law : first, 

 when the original definition includes. two 

 or more species ; and second, when no holo- 

 type is selected and but a single example is 

 figured. Further remarks on these excep- 

 tions follow : 



In cases where a single individual is 

 originally figured, no holotype being se- 

 lected, and the original diagnosis is known 

 to be based upon several examples, it is 

 recommended that the figured one be re- 

 garded as the holotype by subsequent 

 authors. The remaining material described 

 will, therefore, be changed from cotypes to 

 paratypes, since out of the original series the 



holotype has been selected. (See definition 

 of cotype.) 



Where the original diagnosis is without 

 illustrations and contains more than one 

 species based upon cotypes the first subse- 

 quent author is at liberty to select from, 

 these a holotype for the old species, adher- 

 ing as far as can be ascertained to the in- 

 tention of the original author. For the other 

 new species, if any, he may select from the 

 remaining cotypes, or from other material 

 in his possession, the holotypes or cotypes 

 of his new species. 



In cases where a new species is not 

 directly based upon material, but upon the 

 published description of an earlier author, 

 the specimens of the latter become the type 

 material of the new species. The kind of 

 type then present will depend on whether 

 in the original description a holotype had 

 been selected. 



A species described or new and proving to 

 be a synonym does not affect the type ma- 

 terial of the species with which it is 

 synonymous. All such synonymous ma- 

 terial, however, should be carefully pre- 

 served arid marked as holotype or cotype 

 under the original name as well as under 

 the one of which it is known to be a 

 synonym. 



Cotype (or associate type). — Cotype was 

 introduced by Waterhouse, and is defined by 

 Oldfield Thomas as follows : " A cotype is 

 one of two or more specimens together form- 

 ing the basis of a species, no type [holotype] 

 having been selected. No species would have 

 both [holotype] and cotype, but either the 

 former [or holotype and paratype] , or two 

 or more of the latter." In cases where the 

 cotypes are unmarked and cannot be dis- 

 tinguished from the balance of the original 

 series the only safe plan to follow will be 

 to regard all the original material of a new 

 species as cotypes. If such specimens are 

 sent out to collectors and museums they 

 should be marked as cotypes. 



