40 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 89 



The terminal lobes of the second valvifers (figs. 9, 10 C, jVl) 

 might suggest by their usual position that they are the styli of the 

 second gonopods ; but, as will be shown presently, it is certain that 

 they are secondary outgrowths of the gonopod bases. They are here 

 termed " third valvulae " because in the Orthoptera they resemble 

 the first and second valvulae, and form a third pair of blades in the 

 shaft of the ovipositor. Usually the third valvulae ensheath the distal 

 part of the ovipositor between their concave inner surfaces. 



The sclerites termed intervalvulae, lying between the bases of the 

 second valvifers, evidently belong to the venter of the ninth segment, 

 and probably represent sclerotic remnants of the ninth sternum. 



A review of the history of opinion concerning the morphology of 

 the insect ovipositor would occupy more space than its value would 

 justify. The theory here elaborated is essentially that now current 

 with students of insect anatomy, .except that it has not been generally 

 recognized that the first valvifers are the bases of the first gonopods. 

 Some writers have claimed that these plates bearing the first valvulae 

 are derived from the eighth sternum, and others that they are a part of 

 the ninth tergum. The difi^erence of opinion has arisen probably from 

 the fact that the position of the first valvifers relative to the surround- 

 ing parts differs considerably in different insects according to the 

 mechanism of the ovipositor. In some insects the plates clearly belong 

 anatomically to the eighth segment, since they lie in the pleural areas 

 of this segment between the tergum and the sternum ; in others they 

 are dissociated from the eighth segment and are hinged to the second 

 valvifers ; in still others they are definitely articulated with, or attached 

 to, the ninth tergum. If, therefore, the first valvifers appear to be 

 derived in their development from the eighth sternum, the ontogenetic 

 facts mean simply that at an early stage the bases of the first gonopods 

 are not distinguishable from the true sternal area of this segment ; on 

 the other hand, if the first valvifers appear to be cut off from the ninth 

 tergum, it is probable that their phylogenetic history is not fully re- 

 capitulated in their ontogenetic development. The invariable origin of 

 the muscles of the plates in question on the eighth tergum leaves no 

 doubt that the plates belong to the eighth segment, and the fact that 

 the plates always carry the first valvulae would seem to be proof that 

 they are the bases of the first gonopods. 



The term " valvifer " was first introduced into the nomenclature of 

 the ovipositor by Crampton (1917) to designate the sclerite here called 

 " first valvifer " supporting the first, or ventral, valvula, and is so 

 used by Walker (1919). A small plate at the base of the first valvula 

 Crampton called the " basivalvula ". In a later paper containing a 



