xxxiii, '22] ENTOMOLOGICAL NEWS 35 



they are linear, Plate II, fig. 5, in depressa forked, Plate II, fig. 12, 

 while in Orthemis they are hroad flat lobes, Plate II, fig. 13. These 

 lobes are usually easily identified and are the starting point for the 

 identification of the others. 



Medial lobes (marked M in all the figures). These lie entad and 

 ccphalad of the lateral lobes, or dorsad from them if the penis is 

 straightened out. These are usually unchitinized and are not always 

 easily identified until the distal meatus of the seminal vesicles is 

 located. These lobes are the two lips guarding the distal (or apical) 

 meatus. In lydia, Plate III, fig. 16, there is a secondary or inner pair 

 of medial lobes within the outer, larger pair. The medial lobes are 

 usually unchitinized and are somewhat erectile. In jesseana, Plate III, 

 fig. 26, they are covered with papillae when erect. In depressa, if cor- 

 rectly identified, they are chitinized with free ends, Plate II, fig. 12. 



Connta (marked C in all the figures). These are very conspicuous 

 in many species of Sympctrum but are frequently highly modified in 

 Libcllitla. In Sympetrum they are a pair, but in Libellula a third cornu 

 may exist which then lies between the other two. These are unchitinized, 

 except in A-iihieiilata, and arise at the extreme apex of the penis. The 

 cornua are well developed in the primitive scinifasciata, Plate II, fig. 5, 

 where the median one is rudimentary, in saturata, Plate IT, fig. 3, where 

 the right one is asymmetrical, and in Oft lie in is, Plate II, fig. 13. In 

 Orlhetniin, Plate II, fig. 14, if correctly identified, there seems to be but 

 (me. In coinposita. Plate II, fig. 4, nodisticta, Plate II, fig. 6 and -inccstii, 

 Plate II, fig. 10, they are probably represented by the apical tooth, as 

 in coiiiposita : just under the apical tooth are two smaller teeth which 

 may be homologous to the lateral cornua. In jesseana, Plate III, figs. 

 26 and 27, this median cornu is drawn out into a long tail. In anaelinti, 

 Plate II. fig. 7, the cornua are flattened, which specialization is carried 

 much farther in Platliemis, Plate II, fig. 11, and Plate III, fig. 16. 



Internal lobes (marked / in all the figures). These occur in 

 .>\inpelntin but are usually not conspicuous in Libellula, unless they are 

 homologous with the part marked / in the figures of jesseana, Plate 111, 

 figs. 26 and 27. These parts are very erectile and are usually .with- 

 drawn quite completely in the dried penis. 



Posterior lobe (marked P in all the figures). This is an unpaired, 

 very erectile lobe arising on the posterior or ventral surface. It shows 

 in cros> M-rtion in Plate III, fig. 21. It is retracted and not visible in 

 Plate III, fig. 16. It is fully erect in Plate III, fig. 26, of jesseana. 



The least spcriali/ed penis in the' u;eiius Libellula is that of semifas- 

 eiatit. .\ comparison of Plate II. tigs. 1 and 5, will show that it is 

 remarkably like the penis of Syiiipetntin. However, in the various 

 branches of the genus Libellula some very high speciali/ations have 

 come about. The cornna of the satnntta group are fringed, while those 

 of the two Pltitlieinis are short and broad. The apex (cornua?) of the 



