PlATYNIN^ III 



and the Antilles, and it may therefore really be necessary to change 

 the name of thoracica Csy.* 



Group III — melanarium 

 Subgenus Melanagonum nov. 



The rather numerous species of this group are, with very few 

 exceptions, of an intense polished black; in lacuslre (meiallescens 

 Lee.) and in mordax, the elytra become slightly aeneous and the 

 entire upper surface is faintly aeneous in renoicum. So the name 

 adopted seems to be sufficiently warranted. The species are 

 moderate to small in size, with convex surface and more or less 

 strong and usually subimpunctate striae, the basal thoracic angles 

 always very obtuse and usually broadly rounded, but in a few, 

 such as melanarium, the tips of the angles are rather well defined; 

 the sides are regularly rounded as a rule, but in atromicans become 

 more oblique and straight posteriorly, giving the prothorax a more 

 subcordate appearance. According to the number of dorsal punc- 

 tures and degree of reflexion of the thoracic sides, the species may 

 be classified as follows: 



Dorsal punctures of the elytra three in number 2 



Dorsal punctures four or more 12 



* The principle " Once a synonym alvvaj^s a synonym," adopted by Mr. Leng, of 

 course has no application to the cases mentioned above, except to confirm what I have 

 noted, for if the principle be correct Elaphrus poUius Lee, having been made a syn- 

 onjm, must always be considered a synonym, which would liberate the name fo'' 

 another species, the ruling that no two names in a genus can be the same, even if one 

 be an absolute and irrefutable synonym, being an invalid dictum, although of course 

 it is desirable not to have two names alike if it can be avoided. But the principle 

 " Once a synonym always a synonym " is eminently fallacious and lies entirely outside 

 the domain of any sort of necessity. Let us assume, for instance, that some inex- 

 perienced person, through ignorance or perhaps from pique or some other unworthy 

 motive, takes a notion to unite two genera that have always been regarded as distinct, 

 and in doing so changes the name of a species in one of the genera that has been used 

 also in the other. Shortly thereafter an author, composing a general world-wide 

 monograph of the group, demonstrates that beyond any doubt the two genera are 

 distinct. Now under such conditions is it possible that anyone with definite ideas of 

 justice and propriety, could contend that the name substituted by the said person — 

 it may be to replace a name well known for half a century or more in the literature 

 of the subject — would have to be maintained? But on the principle of " Once a 

 synonym always a synonym " this would have to be done. The absurdity of the 

 thing is self evident. I am not criticizing Mr. Leng in any way, for he has simply 

 adopted as official, a ruling of what necessarily must be a limited coterie, which ruling 

 I personally regard as illogical. 



