1907.] NATURAL SCIENCES OF PHILADELrHIA. 227 



The animals are present only sparingly in the infected locusts, and 

 occur in both the mid-gut and p3doric cieca. 



One specimen was observed which showed behind it a gelatinous 

 stalk, such as described by Schewiakoff (1S94), and considered by him 

 to furnish the means for the progressive movement. This stalk, 

 although differing but very slightly in refractive index from the water, 

 could plainly be seen. Since, however, the stalk was carried about Ijy 

 the gregarine as a mammal carries its tail, the sole influence it could 

 have possibly had upon progression would have been that of a hind- 

 rance. 



The actual extrusion of the substance of this stalk was not witnessed , 

 but that the gregarines were liberally provided with some kind of a 

 gelatinous matter was demonstrated by killing them with iodine. 

 Animals so killed showed, on their surfaces, great numbers of small 

 globules. 



I have finally to describe a Geniorhynchiis, probably distinct from 

 the European form. 

 Geniorhynolius aeshnae sp. n. (I'l. XVIII, fig. 4.) 



Epimerite. — Consists of an ellipsoidal or globular head, borne on a 

 short neck which may be considerably swollen. The head is liberally 

 provided with short spines, directed backward. 



Protomerite. — Large, having the form of a truncated cone with 

 slightly curved contours. Broader than the deutomerite. 



Deutomerite. — Conical to cylindrical, terminating bluntly. The 

 posterior fourth generally showed, in the cases observed, one or more 

 deep constrictions, which underwent slow changes. 



Epicyte. — Thin, longitudhially striated. 



Sarcocyte. — Well developed. In the protomerite, it is enormously 

 thickened, occupying the anterior third of the segment as a solid mass, 

 which rapidly thins out behind. It here contains a few small granules. 



Entocyte. — Not especially dense, and usually thinning out consider- 

 ably toward the surface. 



Nucleus. — Shows several irregularl}^ shaped karyosomes. 



Size. — 420 microns long. 



Host. — Nymph of JEshna constricta Sa}'. 



Locality. — Southeastern Pennsylvania. 



