420 
Parasites of the Ground Squirrel 
for trypanosomes every other day during the month of August with 
negative results. The white rats died on Aug. 28 and 30, but no cause 
of death was discovered. The ease with which rats are infected with 
T. lewisi suggests that our Trypanozoon is different. 
Cestoda. 
Collective Genus Cystocercus. 
Gystocercm portolae sp. nov. 
When fully extended the worm is somewhat pyriform (Fig. 7), the 
small end being the head. Neck very short, rostellurn distinct, armed 
with two rows (which appear sometimes like one row very irregularly 
placed) of typical rose thorn hooks (Figs. 8 and 9). Suckers round. 
Epidermis transparent, a dark granular layer immediately beneath it, 
body tissue apparently homogeneous, granular, containing large calcareous 
corpuscles. Measurements of a fully extended specimen as follows: 
Total length 1-2 mm., breadth at widest part 0'406 mm., diameter of 
suckers 0’084 mm., width of rostellurn 0'343 mm., length of rostellurn 
0'28mm., width of neck 0’21mm., average length of long hooks 0'028mm., 
average width of long hooks 0 018 mm., average length of short hooks 
0’019 mm., average width of short hooks 0'013 mm. 
