254 Mr. E. ^smnders'/urtlier notes on the 



I now propose to give a list of the families and 

 genera which I have examined, with remarks on the 

 special characters of each, as exhibited in their apical 

 segments and armature. Of these latter Dufour, in his 

 * Eecherches Anatomiques,' &c., has already described a 

 good many, and his paper is a most important one to 

 anyone working on this subject. I may remark that his 

 " hypotome" is the 8th ventral segment ; his " forceps," 

 the pair of stipites ; his " baguettes du fourreau," the 

 sagittae; his ''volselle," the lacinia of the stipes; his 

 "piece basilaire," the eardo; he only mentions the 

 spatha as the central piece of the " fourreau de la 

 verge." In the following descriptions I have adopted 

 the nomenclature of C. J. Thomson, viz. : — Cardo, the 

 basal portion, in which the two stipites or outer forceps 

 move ; Spatha, the corresjDonding basal portion of the 

 sagittcE or inner forceps, which, however, are often 

 united into a single piece ; Lacinia, the apical pro- 

 duction of the stipes existing in many genera. 



Heterogyna. — In this section the 8th segment is very 

 distinctly represented in both valves, and is generally 

 visible both dorsally and ventrally; the dorsal valve 

 bears two lateral pilose appendages, which seem to have 

 been noticed but misunderstood by some entomologists. 

 Forel, in his Tourmis de la Suisse,' p. 13, regards 

 them as part of the genital armature, calling them 

 "penicilli." E. Andre* also takes this view, calling 

 them "pinceaux," and figures them protruding from 

 under the 7th segment,! and remarks that they project 

 from a square plate situated under the epipygium. In 

 this latter statement he is quite correct, but he does not 

 seem to have realised that this plate is the 8th dorsal 

 segment, and in no way connected with the armature 

 (see PL XIII. , figs. 1, 1 a) ; in fact he says, at p. 13, that 

 the abdomen of the ^ is composed of seven segments. 

 He also remarks that they are often wanting in Myrmi- 

 cocijstus. I cannot help fancying that their apparent 

 absence must be due to the retraction of the 8th 

 segment under the preceding. The most interesting 

 feature in these little tail-like appendages is that they 

 are not simple outgrowths from the segments, but are 

 almost pal^Diform in their nature ; being received into a 



* ' Species cles Formicicles d'Eiirope,' p. 14, f PI. I., fig. 12 a.. 



