2 Maurice Crozvther Hall 



Remarkable conjugations are not uncommon in this g-regarine, 

 and in one instance I observed a case where the sateUite occupied 

 a deep concavity in the posterior part of the deutomerite of the 

 primite. The satelhte was of course very small, the primite being 

 400 ^ long. 



Stcnophora jnlipusiUi displays the characteristic movements at- 

 tributed to it by Leidy (1851) and Crawley (1902-5), and to 

 6". juli by Liihe (1904), constantly withdrawing the protomerite 

 into the deutomerite, moving the protomerite from side to side, 

 and assuming contorted positions from which it recovers with 

 an elastic rebound. 



Hirmocystis rigida n. sp. 



An extensive and careful examination of Mclanoplus during 

 the fall of 1905 from October i to November 30 showed an in- 

 fection with two specie? of gregarines, a yellow form, commonly 

 in conjugates attached by the unlike extremities, and a larger 

 solitary white form. The yellow gregarine I have designated as 

 Hirmocystis rigida owing to the rigidity of its structure. Infec-. 

 tion with this form was practically universal, about 200 specimens 

 being found infected and only ten or fifteen not showing infec- 

 tion on casual inspection. Specimens of Mclanoplus were ob- 

 tained from the country around. Lincoln and also from Scribner, 

 eighty miles northwest of Lincoln. Gregarines were found in all 

 localities investigated and usually in large numbers, as high as 

 400 to 500 in a single host. 



A matter of especial importance in connection with this 

 gregarine is the site of infection. In examining specimens of 

 Melanoplus the method employed was that commonly used for 

 this purpose, to cut off the head and the last two or three abdom- 

 inal segments and then draw out the straight enteric tract with a 

 pair of forceps. Gregarines could usually be found on the exter- 

 nal surface of an intestine so treated, and often in large numbers. 

 On one occasion I washed off about 300 gregarines that were in 

 the body cavity and attached to or lying on the outside of the in- 

 testine. Other similar gregarines were usuallv visible on the in- 

 side of the intestine. 



150 



