168 CALIFORNIA ACADEMY OF SCIENCES. 



(plate xi, figs. 3 and 4). It hence appears that in this 

 species these cells form a compound gland of seven 

 cells, each cell being provided with a duct of its own, 

 the ducts of the several cells uniting and finally form- 

 ing a common duct which opens into the alimentary 

 canal at the mouth of the neck of the crop. In other 

 Ischnoceran genera examined, including Euryinctopus, 

 Docophorus, and Goniodes, these glands are present but 

 the cells in each are more numerous. In Eurymetopus 

 taunts (plate xi, fig. 5), each gland is composed of about 

 twenty-four cells arranged mostly in two rows, although 

 in some specimens, at the posterior end, they are three 

 and four rows wide, so that the gland is posteriorly 

 expanded. Each possesses two nuclear-like bodies, 

 (one of these may be a hollow space into which the 

 duct opens, such spaces being present in salivary cells 

 of insects), and they are all closely pressed together so 

 that they assume polygonal shapes. The presence of 

 a duct is much more difficult to determine than in 

 Trichodectes geomydis, but by removing the oesophagus 

 and crop to a drop of water on a glass slide, as before, 

 and pushing the glands away from the crop, they may 

 be seen to be connected with the latter by a number of 

 fine fibers. Upon focussing down on these with the 

 microscope, one may be seen larger than the rest, pos- 

 sessing a double-bordered appearance characteristic of 

 ducts when viewed with transmitted light. It is 

 attached to the upper end of the crop at one extremity 

 and at the other to the anterior end of the gland, where 

 it divides close to the latter and becomes lost in the 

 cells. By tearing the cells apart there may be seen 

 attached to and ramifying between them, minute, deli- 

 cate processes, apparently tubules. 



A third set of glands opening into the anterior part 



