322 
THE MORPHOLOGY AND BIOLOGY OF HERPETO- 
MONAS PATELLAE, n.sp., PARASITIC IN THE 
LIMPET, PATELLA VULGATA, TOGETHER 
WITH REMARKS ON THE PATHOGENIC SIGNI¬ 
FICANCE OF CERTAIN FLAGELLATES FOUND 
IN INVERTEBRATES. 
By ANNIE PORTER. D.Sc. Lond., F.L.S. 
Beit Memorial Research Fellow. 
(From the Quick Laboratory, Cambridge.) 
(With 17 Text-figures.) 
CONTENTS 
PAGE 
Introduction . . .. .. .. .. .. .. 322 
Observations on living Herpetomonns patellae .. .. .. 323 
Morphology .. .. .. .. .. .. .. .. 323 
Multiplication . . .. .. .. .. .. .. 325 
Nutrition .. .. .. .. .. . . . . .. 326 
Mode of Transmission .. .. .. .. .. .. 326 
Systematic Position .. .. .. .. .. .. 327 
Remarks on the pathogenic significance of certain Flagellates 
found in Invertebrates. .. .. .. .. .. 327 
References .. .. .. .. .. .. .. .. 329 
Introduction. 
Many herpetomonads have been recorded from various insects 
belonging chiefly to the Diptera and Hemiptera, but until the present 
instance, members of this genus of flagellates have not been found 
in the Mollusca and very few in other Invertebrata. Also the habitat 
of the herpetomonads has usually been either the main alimentary 
tract or the haemocoel of their hosts. Digestive glands hitherto have 
not been recorded as being infected. 
Recently, during examinations of a number of the edible limpet, 
Patella vulgata, I was fortunate in finding one infected with a small 
number of minute herpetomonads, the alimentary tract and digestive 
