LANKESTERIA. 81 



secrete an impermeable membrane round themselves and 

 become sporocysts. The sporocysts, when released from the 

 original gametocyst, are broadly spindle-shaped, terminating in 

 a knob-like projection at each end. Each sporocyst contains 

 eight sporozoites, apphed closely to one another in a tight 

 bundle. Sporocyst ruptures at one or both poles while in the 

 ahmentary canal of the larval sand-fly, and the Hberated 

 sporozoites attack the epithelial cells of the gut. 



Dimensions. — Young trophozoite (mtracellular) 23-4/x in 

 length; adult trophozoite (free in gut) 101-4 /* in length 

 by 78 /^ in greatest breadth ; nucleus 30 yu, in length ; karyo- 

 some 8-10 /i in diameter ; gametocyst 66-3-105-1 /* in length ; 

 sporocyst 9-6 /x by 5-8 /u. 



Remarks. — The complete life -cycle of the Gregarine has been 

 described by Short and Swaminath and correlated with the 

 different stages in the life-history of the host. The sporocysts^ 

 of the gregarine are passed out with the eggs by an adult 

 sand-fly. As the larvae hatch out, the sporocysts are taken into 

 their ahmentary canal with their first food. The sporozoites^ 

 invade the epithelial cells, an intracellular stage is passed, 

 and the destruction of the host-cells releases the Gregarinea 

 either in the ahmentary canal or the body-cavity of the larva. 

 The growth of the larvae is accompanied by the growth of the 

 Gregarmes, but in the pupae the Gregarmes in the ahmentary- 

 canal have completely disappeared, and in both pupge and 

 adults adult Gregarines are only found in the body-cavity, 

 where all the other stages of gametogony and sporogony 

 take place. 



Habitat. — Ahmentary canal and body- cavity of the larva,, 

 and m the body- cavity of the pupa and^ adult of the sand-fly, 

 Phlebotomus argentipes Ann. & Brun : Assam ; also in 

 P. papatasii Scop., bred out in the laboratory : Bengal,. 

 Calcutta. 



22. Lankesteria tripteroidesi, sp. nov. (Fig. 24.) 



fA Monocystid Gregarine, Guenther, 1914, pp. 264-7, 5 text-figs. 

 A Gregarine, Wenyon, 1926, p. 1149. 



Trophozoite elongate, with a strongly thickened anterior 

 end which is often spherical and may project laterally. 

 Cytoplasm coarsely alveolar and filled with granules. There 

 are a few vacuoles at the anterior end. Nucleus large, with 

 a shmy protoplasmic thread extending forwards and backwards 

 from it. The nucleus contains large dark nucleoli, which 

 may be one, two, or many in number. 



Habitat. — Body-cavity, respiratory tubes, and anal gills 

 of the larva of the mosquito, Tripteroides dofleini (Guenther), 

 {=Ficalbia dofleini (Guenther)) ■ Ceylon. 



SPOR. Q, 



