2 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 73 



Discussion. — The foregoing case includes two distinct questions. 

 First, is Leucochilus, 1881, an objective synonym of Leucochila, 

 i860? And second, is LettcocJiilus, 1881, a homonym of Leucochila, 

 i860? 



First. — According to the premises, LeucocJiila, i860, has Pupa 

 fallax as type by original designation and this type designation settles 

 for all time the type of Leucochila.^ 



In 1881 Leucochilus is essentially a new generic name, and as Pupa 

 fallax is expressly excluded by Boettger from membership in Leuco- 

 chilus, it is clear that Leucochilus cannot have fallax as its type, and 

 therefore that it is not an objective synonym of Leucochila. 



For Leucochilus, 1881, only one species was mentioned in the 

 original publication, namely. Pupa armifera Say, and this is therefore 

 type of Leucochilus by monotypy.. 



If fallax and armifera are united in one genus, Leucochilus, 1881, 

 becomes a subjective synonym of Leucochila, i860. 



Accordingly, the first question is to be answered as follows : Leuco- 

 chilus, 1881, is theoretically excluded from being an objective syno- 

 nym of Leucochila, i860, but theoretically it might be a subjective 

 synonym. 



Second. — The second question, whether the existence of Leucochila 

 precludes the use of Leucochilus, represents one of a series of cases 

 which the Commission has discussed for more than 25 years, but upon 

 which the Commission has never been able to reach a satisfactory 

 agreement involving an Opinion that can be applied to all cases. The 

 best the Commission has ever been able to do is expressed in the 

 recommendation cf Article 36, which reads as follows : 



It is well to avoid the introduction of new generic names which differ from 

 generic names already in use only in termination or in a slight variation in 

 spelling which might lead to confusion. But when once introduced, such names 

 are not to be rejected on this account. Examples: Picns, Pica; Polyodus, 

 Polyodon, Polyodonta, Polyodontas, Polyodontus. 



In this unsatisfactory status of the results, all the Commission can 

 expect to do is to build up a series of Opinions on special cases in the 

 hope that these Opinions can some day be formulated into a principle. 

 On one occasion a special subcommittee studied the question at issue 

 and reported as follows : 



The Committee is of the opinion that the use of a word as a generic name 

 in one gender does not necessarily preclude its use in a different gender for 

 another genus, but it considers such use eminently undesirable. 



^Leucochila Albers in Von Martens, i860, 296. tod. Pupa fallax Say^ 

 a — for jalla.v, vwdica, clwrdafa. pacifica. 

 b — pcUucida, riisci, corficaria. ripicola, conlracta, annifrra. 



