42 PROTOZOA 



NOCTILUCA Suriray. Body spherical and 1 mm. or less in diameter, 

 with a median groove in which lies a large feeler and a small flagellum, 

 as well as the mouth; single nucleus present; reproduction by division 

 and by spore-formation: 1 species; marine. 



N. miliaris Sur. In the Atlantic and Pacific Oceans; often so plen- 

 tiful that the sea is colored red by day and glows by night with an 

 intense phosphorescent light. 



Class 3. SPOROZOA.* 



Parasitic protozoans which live in the cells, tissues, and open spaces 

 of other animals. The body is usually bounded by a thick cuticula; it 

 has no external openings or contractile or gastric vacuoles, and in most 

 cases but one nucleus. In the adult condition there are no organs of 

 locomotion, although the animals have often the power of sluggish 

 movement. Being entoparasites, all Sporozoa absorb food in a fluid 

 or gaseous form through the outer surface of the body. Reproduction 

 is carried on through the medium of spore formation, which usually 

 follows encystment, the reproductive processes being in many forms 

 very complex. Simple division does not occur. The Sporozoa are very 

 widely distributed, living as parasites in every class of animals from 

 Protozoa to Vertehrata: they are often the cause of disease both in 

 man and the lower animals. The class contains two subclasses and 

 about 400 known species, besides about as many uncertain species. 



Key to the subclasses of Sporozoa: 



©1 Sporozoa in which spore formation ends the individual life, including the great 

 majority of the class 1. Telosporidia 



©3 Sporozoa in which the entire cell does not form spores but sporocysts are 

 formed during life 2. Neosporidia 



Subclass 1. TELOSPORIDIA. 



In these Sporozoa the individual life ends with spore formation, 



the entire cell forming spores: 3 orders. 



Key to the orders of Telosporidia: 



Oi Parasitic as adults in the open spaces and organs of the host. .1. Gregarinida 



©2 Parasitic in the solid tissues and not the open spaces 2. Coccidiida 



Cj Parasitic in the blood of vertebrates 3. H.emosporidiida 



Order 1. GREaARINIDA. 



Usually elongate Sporozoa with a thick cuticula and a distinct 

 nucleus; life history includes two stages, an attached stage, when the 

 animals are known as cephalonts, and a detached and sporulating stage, 



* See "Sporozoa," by A. Labb6, Das Tierreich, 1899. 



