114 T. H, JOHNSTON. 



The characters of the genus Ichthyotaenia as given by 

 Braun 1 are as follows : the presence of a small scolex with 

 four suckers; and there may be a cephalic organ which 

 may be a sucker or a rudiment of a rostellum ; it may be 

 covered exceptionally with small spines ; neck short or 

 long ; segmentation complete ; genital apertures marginal 

 and irregularly alternating ; no uterine opening ; paired 

 vitellaria lying in the sidefields, with numerous follicles ; 

 ovary generally bilobed ; shell gland lying behind ovary. 



It appears to me to be advantageous to restrict this 

 genus by establishing another genus to receive certain 

 species such as those above mentioned, which possess many 

 very constant characters which seem to be of generic 

 importance. It is, therefore, proposed to alter and amplify 

 von Linstow's genus Acanthotaenia, thus : — 



Scolex rather small, with four rounded suckers and an 

 unarmed, non-retractile rostellum which bears a muscular 

 structure (probably an altered apical sucker) at its ex- 

 tremity; segmentation.not generally distinguishable except 

 in mature segments; no overlapping of segments; cuticle 

 of scolex and anterior part of strobila beset with a dense 

 covering of very fine bristles; genitalia single; openings 

 lateral and alternating irregularly; testes numerous, usually 

 in two longitudinal fields lying in front of the ovary; ovary 

 situated in the posterior part of segment, bilobed and 

 usually branched ; shell gland behind ovary; vitellaria in 

 two lateral fields in the cortex ; vagina opening before or 

 behind cirrus; uterus median and tubular, but may give off 

 lateral egg-pouches; eggs thin shelled ; genital ducts pass- 

 ing between the longitudinal excretory vessels. 



It will be noticed that, if we neglect the vitellaria, the 

 genus would easily fall into the super-family Taeniidae and 

 family Dilepinidae, Fuhrmann, possibly into the sub-family 



1 Braun, "Cestodes/' in Bronn's Thierreich, Bd. iv, 1901, p- 1706. 



