HYMENOPTEROUS PARASITES. 279 



anatomical structure is quite different. The fifth apparent (possibly 

 really the sixth) segment is contracted to the tip from which issues a 

 stylet-shaped piece, often curved or hooked at the apex and varying in 

 length from a slight projection to a piece nearly as long as the remainder 

 of the abdomen. The stylus is heavily chitinized and appears to be 

 the terminal abdominal segment. Dissection shows, however, that 

 it is composed of the paired sheaths of the ovipositor. These are 

 crescentic in cross-section and fit closely together along the median 

 line above and to form a hollow tube through which the ovipositor 

 extends. The latter can be only slightly extruded as it is enlarged 

 into a bulb at the base which lies within the last segment and is sup- 

 ported by a chitinous strut ventrally. This apparatus is evidently 

 suited for puncturing quite resistant tissues. 



In Scorpioteleia of the related family BelytidjB an elongation of the 

 terminal abdominal segments occurs, very similar to that shown by 

 the species of Gastrotrypes and by Platygaster tuhulosa. This re- 

 markable genus was first described by Ashmead ('97) from Eastern 

 Canada and later recorded by the present writer ('09) from Wisconsin 

 and the state of Washington. Several other species are known from 

 Europe, which Kieffer ('10) regards as congeneric with Cinetus be- 

 lieving that the modified abdomen of the female is not a good generic 

 character. In the type species, S. mirabilis Ashm., I find upon re- 



FiGURE 2. Scorpiotelia mirabilis Ashm. Abdomen of female in profile. 



examination that the apical prolongation of the abdomen is undoubt- 

 edly retractile as it is not chitinized except toward the apices of the 

 segments and the proportionate lengths of the extruded parts of the 

 latter vary considerably in different individuals. The third, fourth, 

 and fifth segments are tubular, successively smaller, but the sixth and 

 last is of much greater diameter, enlarged at the base, then constricted 

 and then turned upward at the pointed tip. Although the curve is 

 reversed in position, the resemblance to the sting of a scorpion is very 

 striking and suggested the appropriate name of Scorpioteleia. Dis- 

 section shows the last segment to consist of a ventral valve and two 

 dorsal ones, one overlapping the other. The basal piece extends 



