Hanitsch: Blattidae from the Bnitenzorg Museum. 219 



Asymmetry in the wings has apparently not been recorded yet. One 

 would expect it not to be uncommon in organs which lie directly below 

 habitually asymmetrical structures, the tegmina, the venation of which they 

 repeat in their general features. That it does occur, is shown by the case 

 of Phyllodromia diagrammatica which 1 described above (see p. 198), The 

 difference in the branching of the radial and ulnar veins there would, if 

 observed in different specimens, certainly be regarded' as of specific value, 

 and the conditon of the median vein which is simple on the one side, and 

 bifurcated on the other, perhaps even as of generic value ! 



Further, we meet with asymmetry in the tarsus. The tarsus is norm- 

 ally composed of 5 joints, but one of them is frequently suppressed. 

 Brisout de Barneville ^) enumerates ten species of Blattidae in which he ob- 

 served 4 joints only in the one or the other of the tarsi. Those species 

 were, in modern nomenclature: Nyctiborinae: Nyctibora limbata, Thunb., 

 and N. tomentosa, Serv.; Blattinae: Periplaneta americana, L., and Homa- 

 losilpha ustuiata, Burm ; Panchlorinae: Leucophaea suritiamensis, L., and 

 Nauphoeta cinerea, Oliv.; Blaberinae: Blabera atropos, Stoll, and Mona- 

 choda grossa, Thunb.; Corydinae: Polyphaga aegyptiaca, L ; Panesthinae: 

 Panetsliia javanica, Serv. — Brunner VON Wattenwyl ^) confirms de Bar- 

 neville's observation, but adds that the reduction most frequently takes 

 place in the left foot, whilst the right foot has retained the normal number 

 of joints (certain species of Nyctibora^ Epilampra etc.). 



Asymmetry in the case of the supra-anal lamina is rare, but two in- 

 stances may be quoted. In Anisopygia, Saussure (subfam. Phyllodromiinae), 

 from Guatemala, the supra-anal lamina of the (f is divided almost to the 

 base into two unequal lobes. (See Saussure ^) and Shelford ^). And in The- 

 ganopteryx nitida, Borg (subfam. Ectobinae), from Kamerun, that lamina is 

 very asymmetrical, its posterior angles being produced as two incurved 

 hooks, the right overlapping the left ^). 



In the subgenital lamina of the cT asymmetry is exceedingly common. 

 It has been observed in all subfamilies, with the exception of the Blattinae 

 and the Panesthinae, and it frequently happens that within the same genus 

 some species show a symmetrical, others an asymmetrical subgenital lamina. 

 The following genera may serve as examples, though the list is probably 

 by no means exhaustive: 



Subfam. ECTOBINAE: Hemithyrsocera; Theganopteryx; Anaplectai 

 Escala ; Mallotoblatta ; 



Subfam. PHYLLODROMIINAE: Phyllodromia; Ischnoptera; Pseudo- 

 thyrsocera; Piroblatia; Liosilpha; Anisopygia; Ceratinoptera; Paraloboptera; 



'). Annales Soc. entom. France (2), Vol. VI (184s), Bulletin, p. XIX. 



2). Système des Blattaires, p. 13 (1865). 



3). Saussure, Soc. entom. Zürich. Vol. Vlli, p. 57 (1893). 



'*). Shelford, Genera Insectorum, Phyllodromiinae, p. 21 (1908). 



^). Shelford, Trans. Entom. Soc, London 1912, p. 649. 



