THE SPOROZOA 233 



is found in birds. In mammals and in Ichthyopsida numerous species 

 are found. 



Laveran and Mesnil [59] have recently described a species from the 

 intestine of the frog (Rana esculenta\ in which the sporocysts, after being 

 formed in the usual manner, become redissolved, leaving the eight sporo- 

 zoites free in the cyst, thus bringing about secondarily a condition similar 

 to that which characterises the genus Eimeria. The authors consider this 

 form sufficiently distinct to be the type of a new subgenus, and name it 

 Paracoccidium prevoti (Fig. 63). Still more recently [40] these authors 



FIG. 63. 



Cysts of Paracoccidium prevoti, Lav. et Mesn. 

 (par. Rana esculenta). a, cyst with four spores and 

 a cystal residuum (c.r). Each spore contains two 

 sporozoites and a sporal residuum (sp.r). b, ripe 

 cyst in which the sporocysts have become dis- 

 solved, sotting free their contents ; the cyst con- 

 tains eight sporozoites (sp.z), four sporal residua 

 (sp.r), and a cystal residuum (c.r). c.w, cyst-wall. 

 ^ After Laveran and Mesnil [39], x 1000. 



have described a species of Coccidium from the rectum of the tortoise 

 Damonia reevesii, under the name of 0. mitrarium, which is remarkable 

 for having oocysts shaped like a mitre, and is also unique amongst Coccidia 

 in being an extracellular parasite. 



Genus 6. Crystallospora, Labbe", 1896. The dizoic spores have the 

 form of a double pyramid (Fig. 66, /). 



Type-species, Crystallospora crystalloides (Thelohan), from the intestine 

 and pyloric caeca of Motella tricirrata of Roscoff. 



FAMILY 4. POLYSPOROCYSTIDAE, L^ger (Tribe Polysporea, A. Schn.). 

 The oocyst contains numerous spores (chlamydospores). 



Genus 7. Barroussia, A. Schn., 1885. The monozoic spores are 

 spherical, with smooth bivalve shell (sporocyst). 



B. ornata, A. S,chn., type-species, from the gut of Nepa cinerea (Fig. 

 64) ; B. schneideri, Ldger, from the gut of Lithobius impressus ; B. caudata, 

 L4ger, from the gut of Lithobius martini, is referred by Labb6 to Minchinia. 



Genus 8. Echinospora, Le"ger, 1897. The monozoic spores are oval, 

 the bivalve sporocyst is spiny (Fig. 66, c). 



Type -species, E. labbei, Le"ger, from the gut of Lithobius mutabilis. 

 By Schaudinn and others this genus is united with the foregoing. 



Genus 9. Diaspora, Le"ger, 1898. The monozoic spores are oval, the 

 sporocysts are not bivalve, and have a micropyle at one pole (Fig. 66, 6). 



Type-species, D. hydatidea, Leger, from the intestine of the myriapod 

 Polydesmus t in Provence. 



By Schaudinn this genus is united with Barroussia. 



Genus 10. Adelea, A. Schn., 1875. The dizoic spores are spherical 

 or compressed, with smooth sporocysts (Fig. 65). 



Type-species, A. ovata, A. Schn. (see p. 223, Figs. 55 and 56) ; others 

 are A. mesnili, Perez (see p. 206, footnote) ; A. akidium, Le"ger ; A. tipulae, 

 L4ger ; A. dimidiata (A. Schn.), from the gut of Scolopendra morsitans 

 (Fig. 65) ; and A. simplex (A. Schn.), from the gut of the larva of Gyrinus. 



