72 



Rowland M. Shelley 



Fig. 10. Approximate probable distributions of Theatops and the Plutoniuminae 

 in the Western Hemisphere. A smooth line is drawn around range extremes 

 in all directions. 



Opisthomega: Saussure and Humbert, 1872:200. Haase, 1887:78. 



Type species. Of Theatops, Cryptops postica Say, 1821, by subsequent 

 monotypy of Newport (1845). As explained by Crabill (1957), Newport 

 (1844) originally proposed Theatops without mention of included species, 

 but the next year, he (Newport 1845) cited C. postica under it, thereby 

 fixing this as the type species. Opisthemega was proposed for two 

 ostensibly new species, O. postica and O. spinicauda. Wood (1862) 

 did not designate either as the type species, nor did he (Wood 1865) 

 do so in his work on North American myriapods. No one else has 

 done so either, and this action would be redundant now with Opisthemega 

 in synonymy under Theatops. According to Article 12(b)(5) of the 

 International Code of Zoological Nomenclature, genus-group names 

 published before 1931 are available if one or more available species- 

 group names are published in combination with it, or clearly included 

 under it, or clearly referred to it by bibliographic reference. As both 

 postica and spinicauda are valid species-group names, published in 

 accordance with the Code, Opisthemega meets the requirements of 



