Paras . A : 6 



Some of the species with zi^-'^ag patterns have in the lower end a stri- 

 ated object shaped somewhat like a sheaf of grain, apparently the cuticu- 

 lar lining of the vagina (fig. 11). This is nearly always accompanied 

 by a number of dark bodies of irregular, though never angular shape. 

 These may be few or numerous. No constant number or arrangement has 

 been observed. These are absent in cysts of other species having zig- 

 zag patterns and can be used for separation of these cysts into two 

 groups. 



Punctation is found on a layer of the cyst below that which carries the 

 pattern. According to Franklin (1939) punctation is minute pits in one 

 of the layers of the cyst. Under high magnification these appear as 

 round dots of uniform size, either light or dark, according to the focus 

 of the microscope. 



Punctation is usually very prominent in H. rostochiensis and H. punctata , 

 with the dots often iDeing arrayed in distinct parallel horizontal rows 

 (figs. 20 and 2U) . In cysts of the H. schachtii group, punctation is of 

 several types. One of these is a prominent feature of most H. avenae 

 cysts, but also occurs on other species. The dots are about one-half 

 micron in diameter, and there is little or no trace of regular arrange- 

 ment (figs. 25 ana 26), This is called "coarse irregular" punctation. 



Cysts of H. trifolii have dots of about the same size as those fo\ind on 

 cysts of H. avenae , but these are often arranged in parallel lines on 

 part of the cyst at least. This is sho;vn in figure 2? with the lines 

 running diagonally from lower left to upper right across the photograph, 

 but the rows are seldom as long as those shown. 



In other species of the H. schachtii group, fine irregular punctation 

 occurs. The dots of fine irregular punctation are much smaller than those 

 of the coarse type, being difficult to see even with the oil immersion 

 objective of the microscope. Unfortiinately, punctation is a somewhat 

 variable character, being easy to see on some cysts and difficult or 

 impossible to find on others. Its presence is therefore a useful char- 

 acter, but its absence cannot be taken to indicate that a given specimen 

 does not belong to a species for which punctation is described. 



Punctation has not been seen on H. weissi or H. cacti , though it may 

 occur on some of the undescribed species of this group. But cysts of 

 these species often have a grainy appearance (figs. 1? and 18) due to 

 the presence of dots of somewhat irregular size and shape on the outer 

 layer of the cyst. 



The anus of H. cacti is shown in figure 17. All lemon-shaped cysts have 

 the anus located in about this same relationship to the vulva. The anus 

 of H. rostochiensis is shovm near the upper edge of figures 19 and 20. 

 The~pattern runs around the vi^l-va, but the anus is marked only by a 

 slight irregularity. The anus of H. punctata is located at a thin spot 

 on the cyst, which is about the same size as the vulvar opening, figure 

 No. 21 shows this clearly, though the cyst wall was split in the process 



