Constitution of the family Omalidaz. 63 



extraordinary that not one should have occurred in Java." And 

 even when an exotic species is found, it does not present so great 

 a difference of form from the European species as is observable in 

 most of the other groups. The second, and by far the more im- 

 portant reason, is the amazing variety of forms presented to us in 

 the known species, and which when properly investigated, would 

 doubtless be highly useful in pointing out the proper places of 

 other corresponding analogous groups ; as in the case referred to 

 by Mr. MacLeay, in the Annulosa Javanica, of the genus Oxypo- 

 rus possessing similar labial palpi with the genus Engis, 



I have little doubt as to the family Omalidce being a perfectly 

 natural one, consisting of the different genera which Latreille has 

 placed in it, with the exception of Aleochara ; on which I shall 

 now offer a few remarks. I have before stated that I conceive 

 this genus not in its proper position, where Latreille (Cuv. Regne 

 An. 3. 223, and Latreille, Fam. Naturelles, 245) has placed it ; 

 namely, in his division Appldtis ; (Omalidce, MacLeay) and the 

 grounds of this opinion rest, not only on the very different exter- 

 nal appearance which these insects present, but more particu- 

 larly on the 4th joint of the maxillary palpi, (on which Latreille 

 has principally founded his four divisions) and wJiich does not 

 well agree as to size with the description of the same part in the 

 characters of his division Applatis. He says in his description of 

 the last, " les palpes maxillaires avec le quatrieme article dis- 

 tinct;" but describing the same part in the genu^ Aleochara, he 

 says, " le dernier article tres petit " — and in fact, by placing 

 this article at the end of the division, he appears to have been 

 aware of their connexion with the next. In his '' Gen. Crust. & 

 Ins." he has arranged the genera differently, and has placed those 

 of Tachinus, Tachyporus, and Aleochara together, at the end of 

 the Brachelytra, and which appears to me far more natural. I 

 shall only add, that long before I had seen either of the above 

 arrangements by Latreille, I had grouped these three genera to- 

 gether, and had styled them " Aleocharides,^^ and I observe that 

 Messrs. Kirby & Spence, have also made use of the term " Aleo' 

 charidw^^ to designate the same insects. 



Placing then, the Akocharce with the Tachini & Tachypori^ I 



