54 Rowland M. Shelley 



and four Nearctic species. Both the subfamily and the genus Theatops 

 thus demonstrate Holarctic/Laurasian distribution patterns, and their 

 biogeographies are intriguing. In addition to the North American/Euro- 

 pean disjunction in Theatops, allopatric populations exist in three species. 

 In Europe, T erythrocephalus 3 (C. L. Koch) occurs in Croatia, Montenegro, 

 Bosnia-Hercegovina, 4 and the Iberian peninsula, thus exhibiting a hiatus 

 of some 992 km (620 mi) that is partly occupied by P. zwierleini. 

 In North America, T. posticus (Say) occurs east of the Great Plains 

 and in the desert southwest, with an intervening gap of some 1200 

 km (750 mi) (Shelley 1990a), and T. spinicaudus (Wood) occupies 

 two regions in the eastern states segregated by a lacuna ranging from 

 368-688 km (230-430 mi) (Fig. 31). Because of the extensiveness of 

 past collecting, these lacunae are undoubtedly real and are unlikely 

 to change significantly with future discoveries. 



A third genus, Tonkinodentus Schileyko (1992), monotypic from 

 Viet Nam, was assigned to the Theatopinae, but the type and only 

 specimen of its species, Tonkinodentus lestes Schileyko, is missing 

 the last three leg pairs, the caudalmost of which possesses most of 

 the taxonomically critical characters in this subfamily. This genus occurs 

 some 11,200 km (7,000 mi) east-southeast of the most proximate locality 

 of Theatops erythrocephalus in Montenegro and some 11,920 km (7,450 

 mi) west-southwest of that of Theatops posticus in Mexico, and is 

 hence implausible for the Plutoniuminae, which is otherwise geographically 

 coherent. I therefore remove Tonkinodentus from the subfamily and 

 leave it unassigned; proper placement awaits the discovery of fresh 

 material, preferably several individuals, possessing all 21 leg pairs. 

 It should be emphasized in this regard that the proposal of a new 

 taxon is a serious action involving the placement of a new entry on 

 the roster of available scientific names. Future students will have to 

 consider this taxon and address shortcomings in the original account, 

 completely rediagnosing it if necessary, and the proliferation of poorly 

 conceived taxa and substandard accounts by past authors is a major 

 reason for the nascency of myriapodology. It is therefore imperative 



3 Like most chilopods with the -ops generic suffix, confusion has existed over the gender 

 of Theatops and whether it requires the feminine or masculine form of the species-group 

 name. Thus, Kraepelin (1903) reported T. erythrocephalus whereas Attems (1930) cited 

 T. erythrocephala. I (Shelley 1987) reviewed this situation in footnote 2 and noted that 

 article 30 (a) (ii) of the 1984 edition of the International Code of Zoological Nomen- 

 clature supercedes past recommendations and declares that genus-group names ending in 

 -ops are to be considered masculine regardless of derivation or treatment by the author. 

 4 The countries of Slovenia, Croatia, Macedonia, Bosnia-Hercegovina, Montenegro, and Serbia 

 comprise the former country of Yugoslavia. 



