Volume III 
September, 1010 
No. 3 
NEW PROTIST PARASITES FROM THE 
INTESTINE OF TRICHOPTERA. 
By DORIS L. MACKINNON, B.Sc. 
(.Assistant in the Zoology Department, University College, Dundee.) 
(With Plate XVIII.) 
When examining the contents of the alimentary canal of caddis-fR 
larvae, I found that in addition to certain well-known gregarines, they 
generally harbour several other interesting protist parasites which have 
not hitherto been described. Chief among these are : (a) a tricho- 
mastix, ( b ) a spirochaete, and (c) a flagellate which appears to be related 
to Macrostoma caulleryi, Alexieff. The present paper deals with the 
trichomastix and the spirochaete: I hope to describe the other flagellate 
fully in a future communication. 
(a) Trichomastix triehopterae, n. sp. 
I. Systematic position. 
The trichomonads form a well-marked group of flagellate parasites, 
characterized by a skeletal axial rod and four flagella springing from the 
extreme anterior end of the pear-shaped body ; three of these flagella 
are directed forward, the fourth is either a free, backward-directed 
“ Schleppgeissel ” ( Trichomastix , Biitschli), or is attached along the 
body by an undulating membrane ( Trichomonas , Donne). 
The genus Trichomastix contains three well-authenticated species— 
Trichomastix lacertae, Biitschli, T. serpentis, Dobell, and T. batrachorum, 
Dobell. Trichomastix caviae (Davaine) is sometimes included here, 
though Grassi’s description of the flagella is rather uncertain. As their 
specific names imply, these forms are all parasitic in vertebrates. 
Grassi, however, states that he saw in the intestine of Blatta a parasite 
Parasitology in 
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