SPECIAL MORPHOLOGY AND TAXONOMY OF SPOROZOA 437 



of which are so characteristic that they have received the name of 

 coccidin. They are all osmotic in nutrition, and infection is always, 

 so far as known, by the contaminative method through the digestive 

 tract. The sporozoite penetrates an epithelial or other definitive 

 cell, grows at the expense of the cell which it ultimately destroys, 

 and forms agametes while still intracellular. Cydospora karyolytica, 

 Schaud. of the ground mole enters the nucleus of the intestinal epi- 

 thelial cell and as a karyozoic parasite completes its life history. 



We follow Doflein in dividing the Coccidia into two families the 

 Adeleidae and the Eimeriidae, each further divided into sub-families 

 as follows: 



Family 1 . Adeleidse, Leger. Forms with a small number, usually four, 

 of non-fiagellated gametes derived from a microgametocy te , macro- and 

 microgametocytes sexually differentiated and united in more or less youthful 

 stages in pseudoconjugation. Four sub-famiUes are recognized, tliree of 

 them characterized by Leger but the grouping should be regarded as ten- 

 tative until further knowledge of the different genera is forthcoming. 



Sub-family 1. Legerellinae, Leger. The single genus included here is 

 said to be characterized by sexually differentiated agametes. Sporozoites 

 are formed directly by the zygote without sporoblasts, zygote with two or 

 three cyst membranes. 



1. Genus Legerella, Mesnil. With four microgametes ; Malpighian tubules 



of species of Glomeris. 



Sub-family 2. Adeleinae, Leger. Sporozoites two or four in number in 

 each sporoblast , sporol)lasts oval and discoid four or more in number in each 

 sporocyst. 



2. Genus Adelea, A. Schn. Many sporoblasts formed in each cyst; each 



sporoblast with two sporozoites arranged tete a tete; gut of Lith- 

 obius fortificatus and of insects. 



3. Genus Adelina, A. Schn. With thick-walled spherical sporoblasts 



formed in a thick walled cyst; different tracheates. 



4. Genus Chagasia, Leger. A possibly allied form with sporoblasts each 



with four sporozoites; from the Brazilian hemipteron Dysdercus 

 ruficollis L. 



5. Genus Hyaloklossia, Labbe (1899). Numerous sporoblasts with two 



or four sporozoites. 



6. Genus Minchinia, Labbe (1899). Many sporoblasts each with two 



sporozoites and with two long threads; liver of Chiton and Patella 

 species. 



7. Genus Klossia, A. Schn. (1875). Sporocyst with a large number (up 



to 160) of globular sporoblasts each with four sporozoites; kidney 

 parasites of land snails (species of HeHx and Succinia). 



8. Genus Orcheobius, Kunze (1907). Macrogamete very large and worm- 



like; microgametocy te much smaller forming four microgametes, 

 sporoblasts globular, twenty-five to thirty m number and each with 

 four sporozoites, testis of Herpobdella atomaria {Nephelis vulgaris). 



Sub-family 3. Haemogregarinse, Leger (m part) Fig. 177. The hemo- 

 gregarines are Adeleidaj parasitic in the blood cells of vertebrates in which 

 the asexual phase occurs, the sexual phase is carried on for the most part 



