GENERA: HEXAMASTIX AND COCHLOSOMA 681 



Mackinnon appears to be the same as P. melolonthcB of the cockchafer 

 (Fig. 283). The body is pear-shaped, with a rounded anterior and pointed 

 posterior end, which may be forked or otherwise deformed. There are 

 four flagella arising in pairs from two blepharoplasts at the anterior end 

 of the flagellate. Between the blepharoplasts, according to Mackinnon, 

 there is a cytostome. The nucleus lies just behind the blepharoplasts, 

 and it is spherical or pear-shaped. It contains a large karyosome. A 

 characteristic feature of the flagellate is the presence of a definite rigid 

 periplast, which is raised into ridges or folds which run in a more or less 

 longitudinal direction. An axostyle is present, but is not always well 

 developed. The flagellate multiplies in a somewhat curious manner. 

 The karyosome becomes dumb-bell-shaped and then divided, and this is 

 followed by division of the nucleus. One nucleus, together with one of the 

 blepharoplasts and its two flagella, and part of certain granules which lie 

 just anterior to the nucleus, become gradually transferred to the posterior 

 end of the organism which elongates. The body is then divided by 

 constriction across the middle. This form is of interest in that it shows 

 features which characterize some of the highly complicated forms included 

 in the order Hypermastigida, such as Lojphomonas hlattanmi, a flagellate 

 which occurs in the intestine of the cockroach (Fig. 286). The mode of 

 division of L, hlattarum, is very similar to that of Polymastix melolo7ithce, 

 while the superficial periplast may show longitudinal markings. 



Genus: Hexamastix Alexeieff, 1912. 

 This genus was created by Alexeieff (19126) for a flagellate of the 

 intestine of the newt, Triton tceniafiis. The flagellate resembles in all 

 essential respects a member of the genus Eutricho- 

 iiiastix, except that there are six flagella. It was 

 first placed by Alexeieff (1911) in the genus Poly- 

 mastix, from which he removed it in 1912. It may 

 be related to the forms of Tricliomonas with five 

 anterior flagella. 



Genus: Cochlosoma Kotlan, 1923. 



This genus was created by Kotlan (1923) for an ^ ^„, ^ „ 



., „ „ • 1 • n 11 • • i- Fig. 284. — Cochlosoma 



ovoid flagellate with six flagella arising from a a««iw Kotlan 1923 



blepharoplast at the anterior end of the body from the Cecum op 



(Fig. 284). Behind the blepharoplast was a single the Duck (x 2,000). 



nucleus, while two fibres arising from the blepharo- '^ J7^^ otlan, 



plast passed backwards through the cytoplasm, one 



on each side of the nucleus, to the posterior end of the body, through 



which they protruded. The characteristic feature of the flagellate, 



