Transactions of The Royal Society of Canada 



SECTION IV 

 Series III JUN E 1914 Vol. VIII 



On the Systematic Position of Haplobothrium globuliforme Cooper. 



By A. R. Cooper, M. A., Biological Department, University of Toronto. 



Presented by Dr. J. J. MacKenzie. 



(Read May 26, 1914.) 



In endeavouring to locate this new genus of cestode in the most 

 recent classification of the Pseudophyllidea by Luehe ('02) such diffi- 

 culty was encountered that it was considered advisable to discuss its 

 relationships somewhat at length with the view to showing the neces- 

 sity of a modification of the classification in order to accommodate 

 such a most interesting form. 



Before proceeding, the characters of the genus and species, of 

 which a detailed description is soon to appear, will be given in brief 

 for the purpose of immediate reference: 



Genus: Haplobothrium Cooper ('airAoos, simple; fiotipiov, a small hollow 

 or trench). 



Scolex apparently unarmed, although the edges of the terminal disc and 

 auricular appendages of both scolex and anterior proglottides are provided 

 with very minute spines. Bothria, two shallow depressions on the dorsal and 

 ventral surfaces, very simple in structure. Neck absent, proglottidation 

 beginning immediately behind the scolex, but present in the anterior end 

 only of the stobila, the hinder portion being quite ligulate. Foremost joints, 

 long and narrow, provided with appendages which disappear farther back. 

 Nervous system consists of two chief strands situated in the medullary 

 parenchyma outside of the vitelline follicles, uniting anteriorly to form 

 a very small nerve-ring, and eight collateral strands, four arranged around 

 each main tract, the latter in the jointed portion of the strobila only. 

 Excoretory system is made up of one larger median vessel, slightly dorsally 

 situated, and two smaller, lateral and ventral, all uniting in the scolex 

 behind the nerve-ring to form a median vesicle. Genital organs simple. 

 Genital pores on the ventral surface, that of the vagina close behind the 

 cirrus-opening towards the anterior end of the proglottis; opening of the 

 uterus much farther back, a temporary aperture only. No genital atrium 

 or cloaca. Ovary and shell-gland median, respectively ventral and dorsal. 

 Vitelline glands composed of numerous follicles arranged cylindrically 

 around the testes, both within the longtiudinal muscles of the parenchyma. 

 Large vitelline reservoir. Testes all in one plane, separated into two re- 

 gions by the median excretory vessel. Vitelline glands and testes laterally 

 situated opposite the genital ducts, thus leaving a clear "middle-field." 

 Vas-deferens provided with a sperm-reservoir at its posterior end near the 

 middle of the proglottis; whole course of the duct dorsal to the uterine 

 Sec. IV, 1914 — 1 



