6o4 



CESTOIDEA 



[b) Egg round or oval; outer membrane, 54 to 86 fi; 

 yellowish; may be radially striated; inner 

 membrane, 24 to 40 /i, X 20 to 35 fx, with not 

 very evident mammillate projection at each 

 pole- — H, diminuia. 

 {c) Egg oval or spherical; outer membrane, 50 to 

 100 /X X 35 to 100 /x; inner membrane, 30 to 40 

 X 25 /x; occasionally polar papillae; very rare 

 in man — H. lanceolata. 



(2) Egg in Capsules. 



{a) Eight to twenty eggs in a capsule; egg spherical, 43 

 to 50 fjL — Dipylidium caninum. 



[b) One to three eggs in a capsule, with calcareous 



corpuscles. Eggs with two shells and two 

 mammillate projections; onchosphere, 8 /i- — ■ 

 Davainea madagascariensis. 



[c] Egg capsules without calcareous corpuscles ; mature 



eggs not observed — D. asiaiica. 



ORDER I. PSEUDOPHYLLIDEA Cams. 



This order has three families: (i) Dibothriocephalidse ; (2) Ptychobothriidae ; 

 (3) Amphitretidae. The first only contains human parasites. 



Family Dibothriocephalid^. — Pseudophyllidse, with variously developed 

 suckers, and a uterus which forms a rosette. Eggs with opercula. There 

 are two subfamilies with species found in man: (i) Dibothriocephalinse ; 

 (2) Ligulinae. 



Subfamily i. Dibothriocephalin^. — The suckers or bothria are more or 

 less definite slit-like furrows. Proglottides distinct, and drop off in groups. 

 Genus i. Dibothnocephalus ; Genus 2. Diplogonoporus ; Genus 3. Sparganum. 



DibothriocephalusLiihe, 1899. 



Synonyms. — Diphyllobothrium Cobbold, 1858 (considered to be correct name 

 by some authors); Bothriocephalus pro parte Rudolphi, 1819; Dibothrius pro 

 parte Rudolphi, 1819; Dibothrium pro parte Diesing, 1850. 



Dibothriocephalinae, with a more or less elongated, unarmed scolex with 

 flat suckers cutting deeply into the head. Single genitalia in each proglottis, 

 (i) Dibothriocephalus latus ; (2) D. cordatus ; (3) D. cristatus ; (4) D. parvus. 



Dibothrioeephalus latus Linnaeus, 1748. 



Synonyms. — Tania lata L., 1 748 ; T. vulgaris L., 1 748 ; T. membraneacea Pallas, 

 1781; T. tenella Pallas, 1781; T. dentata Batsch, 1786; T.grisea Pallas, 1796; 

 Bothriocephalus latus Bremser, 1819 ; Dibothrium latus Diesing, 1830; B. balticus 

 Kiichenmeister, 1855; B. cristatus Davaine, 1874; B. latissimus Bugn, 1886. 



History. — This tapeworm has long been known in Europe, especially in 

 French Switzerland and the Baltic provinces, Germany, and in many other 

 parts. It is, however, well known in Asia, Turkestan, and Japan; in Africa 

 about the Lake N'gami, in Madagascar, and in North America. 



It occurs in man, and dogs and cats. 



Morphology. — It is about 9 metres in length, with some 3,000 to 4,200 seg- 

 ments; colour yellowish-grey. Scolex elongated, almond-shaped; 2'5 milli- 

 metres in length, with two deep laterally place suckers. Neck very narrow, 

 and of variable length. 



Proglottides very broad (10 to 20 millimetres), breadth being greater than 

 the length; postero-lateral angles project. Testes situated dorsally; vas 

 deferens has a vesicula seminalis and a cirrus sac which opens dorsally. 

 Vaginal opening directly behind this, leading into a receptaculum seminis. 

 Yolk glands in pairs, shell gland behind, ovaries on each side of the median 

 line behind. Uterus is arranged in a rosette, with four to six convolutions, 



