
572 RECORDS OF THE S.A. MUSEUM 
number, with two single flame-cells in (he tail stem, the formula is different from 
that of C, lesson?. The metacerearia of both these forms is found in tadpoles. 
C. dohema Cort and Brackett (hosts, Slagnicolu and Limnaca) resembles 
our cerearia in size, spination, presence of eyespots and a posterior excretory 
commissure, and in the excretory tubes of the tail, which open half-way along 
the furcae; but the exeretory system though of the same fundamental pattern, 
is less complex, its formula being 2[2-+ (2-+ (1))]; there are only six glands 
lying behind the ventral suckev; the digestive system is greatly reduced. 
C, angelae Johnston and Simpson 1944 (from Ameridun), has somewhat similar 
spination, fwo groups of four gland-cells, in tandem, an excretory commissure 
behind the ventral sucker, and a single pair of flame-cells high in the tail stem ; but 
the grouping of the flame-cells in the body is different, and the fureal exeretory 
tubes open at the tips. The excretory system of C. bulbocanda Miller (from 
Planorbis) appears to be identical with that of C, lessont, but the nature of the 
tail and digestive system excludes it from immediate relationship. C, hirsuta 
Miller and C. granula Miller (both from Planorbis) exhibit some features in 
common with our cerearia, including exeretory systems of similar but not identical 
formulae; but both forms possess a greatly reduced digestive system, and a very 
large number of small glands behind the ventral sucker. 
C, furcicauda Faust, C. robusticauda Faust, and the cerearia of Neodiplo- 
stomum lucidum (La Rue and Bosioa) have each a single flame-cell pair bigh in 
the tail, and excretory pores halfway along the fureae, but in none of these 
three is the arrangement. of the flame-cells exactly similar to that of C. lessont, 
while the absence of a posterior commissure, and the number and arrangement 
of the gland-eells, indicate that, though some relationship is possible, it is mot 
close, 
C. gracillima Faust (from Physa aud Limaaen), (. bdelloeystes Lutz (from 
Planorbis) and C, longiremis Wesenberg-Lund (from Valvala) may be related 
species, but (he descriptions are adequate to verify this. C. bdellocystis is said 
to encyst in leeches and develop into Apetemon bdellocystis (in pigeons, 
experimentally). 
Furcoeerearia T Petersen (from Limnaea aud Physa) has two groups of 
threo gland-cells, and an excretory commissinre posterior to the veutral sucker; 
the body proportions, spination and contractility ave similar to C. lesson, but 
the excretory system as indicated in the diagram shows a number of (differences. 
C. secobii Faust (from Liniiaea and Physa) bas four pairs of gland-cells in 
taudem but, though the excretory system is uot known, the large size of the tail 
makes close relationship with @. lessont improbable. 
(!. ranae Cort and Brackett has eyespots aud a commissure inore or less 
behind the ventral sucker, but is distinguished from our cerearia hy the gland- 
