354 Rules for Rendering the Nomenchture of Zoology Uniform. 



act of justice to the original author that his generic name should 

 never be lost sight of; and it is no less essential to the welfare of the 

 science, that all which is sound in its nomenclature should remain un- 

 altered amid the additions which are continually being made to it. On 

 this ground we recommend the adoption of the following rule : 



i^ 3. A generic name, when once established, should never be can- 

 celed in any subsequent subdivision of the group, but retained in a 

 restricted sense for one of the constituent portions. 



Generic names to be retaiwd for the typical portion of the old genus. — 

 When a genus is subdivided into other genera, the orignal name should 

 be retained for that portion of it which exhibits in the greatest degree 

 its essential characters as at first defined. Authors frequently indicate 

 this by selecting some one species as a fixed point of reference, which 

 they term the " type of the genus." When they omit doing so, it may 

 still in many cases be correctly inferred that the first species men- 

 tioned on their list, if found accurately to agree with their definition, 

 was regarded by them as the type. A specific name or its synonyms 

 will also often serve to point out the particular species which by im- 

 plication must be regarded as the original type of a genus. In such 

 cases we are justified in restoring the name of the old genus to its typ- 

 ical signification, even when later authors have done otherwise. We 

 submit, therefore, that 



§ 4. The generic name should always be retained for that portion of 

 the original genus which was considered typical by the author. 



Examjjie. — The genus Picumnus was established by Temminck, and 

 included two groups, one with four toes, the other with three, the 

 former of which was regarded by the author as typical. Swainson, 

 however, in raising these groups at a later period to the rank of genera, 

 gave a new name, Asthenuriis, to the former group, and retained Picum- 

 nus for the latter. In this case we have no choice but to restore the 

 name Picumnus, Tem., to its correct sense, canceling the name Asthe- 

 nurus, Sw., and imposing a new name on the three-toed group which 

 Swainson had called Picumnus. 



When no type is indicated, then the original name is to be Icept for that 

 subsequent subdivision ivliich first received it. Our next proposition seems 

 to require no explanation : 



i^ 5. When the evidence as to the original type of a genus is not 

 perfectly clear and indisputable, then the person who first subdivides 

 the genus may alfix the original name to any portion of it at his dis- 

 cretion, and no later author has a right to transfer that name to any 

 other part of the original genus. 



A later name of the same extent as an earlier to be wholly canceled. — 



