96 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



of the genus Echeneibothrium are further illustrated by the 

 study of the species known as E. minimum, van Beneden* ; 

 E. gracile, Zschokket; and Rhinebothrium spp. LintonJ. 

 The species E. minimum described by van Beneden is 

 characterised by the presence of Echeneiform bothridia 

 divided by transverse, but not (apparently) by longitudinal 

 costae ; by the presence of a long neck ; and by the presence 

 of a group of fairly long spines at the base of the cirrus. 

 E. gracile has Echeneiform bothridia divided by both 

 transverse and longitudinal costae ; it has no neck, the 

 segmentation of the strobila being continued right up to 

 the scolex ; and it does not possess the group of long spines 

 at the base of the cirrus. Rhinebothrium resembles the 

 genus Echeneibothrium in most characters, but it was 

 founded by Linton to include cestodes possessing Echenei- 

 form bothridia, but lacking the peculiar myzorhynchus 

 possessed by such a species as E. variabile. 



There is no ambiguity in the descriptions or figures of 

 the authors quoted. P. J. van Beneden figures the 

 bothridia of E. minimum most clearly and indicates no 

 longitudinal costa, but certainly represents a long neck, 

 and a most distinct group of long spines at the base of the 

 cirrus. Zschokke, on the other hand, just as clearly des- 

 cribes and figures his worm as possessing longitudinal 

 costae, no spines at the base of the cirrus, and no neck. 

 No one would have difficulty in drawing up a table of 

 specific differences. 



Unfortunately the cestode described here combines 



* "Vers Cestoides," p. 114, PI. II. 



f " Recherches sur la Structure anatomique et histologique des 

 Cestodes." Mem. Vlnst. Nat. Oenevois ; T. 17, pp. 348-356, PI. IX. 

 Geneve, 1889. 



t " Notes on Entozoa of Marine Fishes of New England with 

 descriptions of several new species " ; Commissioners' Report for 1887 : 

 United States Commission of Fish and Fisheries, pp. 768-778, Pis. Y- 

 VI. Washington, 1891. 



