536 HYMENOPTERA 



CHAP. 



The genus Scleroderma consists of small Insects much resembling 

 ants, and, as well as some of its allies, is of great interest from 

 the remarkable phenomena of polymorphism presented by certain 

 species. The males in this genus are winged, the females com- 

 pletely apterous ; yet at times winged females are produced as 

 exceptional individuals in a brood of wingless specimens the 

 females in these cases being not only winged, but possessed of 

 ocelli like the females of other winged Hymenoptera. Particulars 

 of a case of this kind have been given by Sir Sidney Saunders, 1 

 and Ashmead also mentions 2 the exceptional occurrence of these 

 winged females. Westwood 3 was of opinion that there are three 

 forms of the female sex. This subject is of importance in con- 

 nexion with the production of the various castes in ants. 

 Although the presence of wings in these Insects is always 

 rt accompanied by the existence of ocelli 



(which, it will be remembered, are normally 

 absent from the wingless individuals), yet 

 the converse is not always the case, for a 

 form of the female of Cephalonomia for- 

 miciformis, without any wings, yet having 

 ocelli, as well as eyes, well developed, is 

 figured by Westwood. 4 



The development of some of the Proc- 

 totrypids has been partially described by 

 Ganin and others, and is of an extra- 

 ordinary character. Ganin's observations 5 



Fie. 353. Cyclops form of 



larva of piatygaster sp. were most complete in the case ol a 

 (After Ganin.) a, Mouth; S p ec ies of Piatygaster, which he found in 



o, antenna ; c, claw- 



limb; d, lower lip (the the larva of a very minute Dipteron of 

 pointing line is a little the ug Cecidomyia. The Piatygaster 



too short) ; e, doubtful 



"zapfenfdrmig" organ;/, larva changes its form very much in the 



o V f i the 1 t k a e ii 10be;fif ' t)ranCh course of its life > resembling at first a 

 minute Crustacean rather than an Insect- 

 larva ; it has a very large rounded anterior portion, while 

 behind it terminates in two, or more, tail-like processes. By a 



1 Tr. ent. Soc. London, 1881, p. 109. 



2 Bull. U. S. Museum, No. 45, 1893, p. 28. 



3 Tr. ent. Soc. London, 1881, p. 117. 



4 Tr. ent. Soc. London, 1881, pt. vi. f. 3 ; pp. 120, 126. 



5 Zeitschr. wiss. Zool. xix. 1869 ; Ganin's observations are described by 

 Lubbock, Origin and Metamorphoses of Insects, 1874, p. 34. 



