THE PEOTOZOA (continued} 



SECTION K. THE SPOROZOA l 



CLASS SPOEOZOA. 



SUB-CLASS TELOSPORIDIA. 



Order 1. Gregarinida. 

 2. Coccidiidea. 

 ,. 3. Haemosporidia. 



SUB-CLASS NEOSPORIDIA. 



Order 4. Myxosporidia. 

 5. Sarcosporidia. 



INCERTAE SEDIS. 



Order 6. Haplosporidia. 

 ,, 7. Serosporidia. 

 8. Exosporidia. 



INTRODUCTORY. The Sporozoa are a group of exclusively para- 

 sitic Protozoa, of very widespread occurrence, infesting the 

 internal organs or tissues of animals belonging to almost all classes 

 and orders of coelomate Metazoa. There is perhaps no species of 

 annelid, mollusc, arthropod, or vertebrate which is not liable to 

 become the host of some kind of sporozoan parasite, at any rate 

 in certain localities, while many animals harbour several species of 

 these intruders at the same time. Moreover, in some cases, as, 

 for instance, that of the common earthworm, or the mealworm, 2 

 scarcely an individual can be found which does not contain more 

 or fewer of its particular form of sporozoan parasite. Correlated 

 with their wide distribution, the Sporozoa exhibit the utmost 

 diversity of structural and developmental characters. As a 



1 By E. A. Minchin, M.A., Professor of Zoology, University College, London. 

 2 The larva of the meal-beetle, Tenebrio molitor. 



