

580 RECORDS OF THE S.A. MUSEUM 
of similarity between C. ameriannae and most of the last-named group is the 
possession of four pre-acetabular gland-cells, and two pairs of flame-cells in the 
tail, This last characteristic distinguishes C. ameriannae at once from such 
cercariae as C. indica I Sewell, €, furcicuuda Faust, and C. Neodiplastomi-lucidr 
(La Rue and Bosma), whieh, though possessing four gland-cells, have only two 
flame-eells in the tail, near the junetion of the body. 
Our cerearia is rather more closely allied to a number of cereariae which, 
besides possessing four Gland-cells, have several other significant features in 
common with C. ameriannae. C, chrysenterica Miller, from Limnaea megasoma, 
is among these. The body of this cerearia is very slightly larger, but the propor- 
tions are similar, As in C. ameriannae, the eacca are distended posterior to the 
ventral sucker, The spination on both is similar. The genital primordium of 
each is wedge-shaped. The excretory systems differ in one point, for, though 
there are fourteen flame-eells in the body and four in the tail in each, the 
formala for C. chrysenterica is 2{(8-- 1) + (2+ 2+ (2))] =18, instead of 
2[(2-+ 2) + (2+1-+ (2))] =18 as in () ameriawnae. Other differences are 
in the caudal bodies: (. ameriannae has none, whereas (. chrysenterica has several 
small irregular ones; and in the gland-cells which, though ventral to the caeea, 
four in number, and of similar size to those in C!, wneriannae, ave post-acetabular 
in position. They ave, however, arranged in a grouping rather similar to that of 
the gland-eclls in our cerearia, The second intermediate host of C. ehrysenterica 
is unknown. 
C. sudanensis No. 5 (Archibald and Marshall), from Bulinus, may be even 
more closely allied to C. ameriannae, Lt is unfortunate that its excretory system 
has not been described, for in all other respeets, and most particularly with regard 
to the shape of the caeca, it resembles (. ameriannae very strongly, as far as can 
be determined from the description and figure. The major difference is that the 
two median gland-eells are situated slightly anterior to the two lateral cells, This 
arrangement is seen again in C. letifera (fnuhrmann), from Limnaea; but in this 
cercaria, the ecaeca are shorter and dilate less abruptly than in 
C. amariannae, there is one fewer flanie-vell on each side (the formula is 
2[(2-+ 2) + (2+ (2))] =16), and there are well-developed eaudal bodies. 
C. tenuis Miller has four pre-acctabular gland cells with the same arrangement, 
but the caeea are shorter and are not dilated, and the flame-cell formula is 
21 (2) + (24-14 (2))] =14 
C. Diplostami-spathacet (Rudolphi) (=C. helvetica XX XI Dubois), 
C. Diplostomi-flenicaudi Cort and Brooks, and C. Diplostomi-murrayensis Johuston 
and Cleland, all from species of Limnava, are related to C. ameriannag. The 
important differences in these ecereariae are firstly, that in all three the glands, 
