164 THE CANADIAN ENTOMOLOGIST. 



A SYNONYMIC NOTE ON CERTAIN BELOSTOMID^ 



(HEMiPTERA). 



BY G. W. KIRKALDY, HONOLULU, H. ISLANDS. 



This brief note is in response to my friend Mr. Bneno's mention of 

 further synonymy, in his recent valuable paper (Can. Ent., Vol. XXXIX, 



PP 333-340- 



It is now generally accepted, by workers at aquatic hemiptera, that 



the generic name Belostoma must be conferred upon the species formerly 



known as " Zaitha," the single species arranged under the former, at its 



inception, being a " Zaitha." This requires no further comment, but 



some consideration is necessary to select the correct name for the now 



nameless genus, " Belostonia^' olim. 



Stal, in 1865 (Hem. Afr., Ill, 179), separated, from ^'- Belostoma^'^ 

 those forms with strongly-widened lateral margins to the pronotum 

 {coilosiciwi, etc.), under the name Amorgins, and unaware of previous 

 names, I adopted this, in my recent list of Pagiopod genera, for the old 

 '' Beiosto?na,'^ accepting Mo?ita?ido?iista (iQor) as a subgenus for the 

 narrow-margined forms. There is no doubt, however, that Lethoceriis 

 (Mayr, 1852, Verh-Zool. bot. Ges-Wien, V, 17) is the same as Mojita7i- 

 doTiista, and that Lethocerus cor dof anus (I. c.) must take precedence of 

 Amorgittr ( Moniandonista) niloticus. 



Lethocerus^ however, was founded on a nymph, and was therefore 

 rejected by Mayr himself in 1863 and 187 1, as well as by Stal, 

 Montandon and Champion. But, according to the general rules of nomen- 

 clature, genera and species founded on immature stages are valid, though 

 as a rule they are not advisable. Therefore, Lethocerus must be reinstated. 



The following synonymy will summarize the above : 



T. Belostovia Latreille, 1807 (type testaceopalliduvi)^ = Zaitha, Am. 



and Serv., 1843. 



2.* Lethocerus, Mayr, 1852 (type cjrdo/auus), = Be/ostoma, auctt., 

 = Mo7itando7iista, Kirkaldy, 1901, subgen, Amorgius, Slal, 1865. 



The species Be/ostona nilotica (Stal, 1854) should therefore be known 

 as Lethocerus cordofauus 



The above is a good instance of the folly of refraining from adjust- 

 ments of synonymy wheji their necessity is discovered. Mayr knew in 

 1871 that the proper name of " Zaitha" was Belostonia, and. that that of 

 " Belostoma " was Lethocerus. Those changes were infinitely easier to 

 make 37 years ago than now, and correspondingly (or more so) easier now 

 than 37 years hence. 



* Incorrectly included by me formerly in Hydroryrius, i.e., Diplonychus, 

 May, 1908 



