674 SUMMARY OF CURRENT RESEARCHES RELATING TO 



reuamed Megastoma entericum. Posterior extremity bifid; a deep 

 depression near the anterior end. 



3. Lophomonadidea Grassi. Posterior extremity more or less 

 tapering ; a knob, carrying numerous fiagella, on tlie anterior 

 extremity. 



4. TricJiomonadidea Grassi (new). Posterior extremity as in 1 

 and 3 ; anterior extremity provided with several flagella, as well as 

 trichocyst-like bodies. 



5. Trypanosomata Kent. An undulating margin to the body, pro- 

 longed at one end into a flagellum. 



Under Fam. 1 are included the genera Monocercomonas (contain- 

 ing, inter alia, a species named M. insectorum = Schedoacercomonas 

 melolonthcB and grijllotalpce of the former paper), Gimoenomonas n. gen., 

 based on Trichomonas batrachorum Perty, Plagiomonas n. gen., based 

 on Betortamonas gri/llotalpcB Grassi, Monamita n. gen., for Cercomonas 

 muscce-domesticoE Stein, Heteromita and Dicercomonas Duj. Without 

 going into various (in part apparently gratuitous) changes introduced 

 into the synonymy, it may be pointed out that the variety of hosts in 

 which many of the forms are now found renders it unadvisable to 

 name a species after any one host. 



Fam. 2 embraces Dimorphus muris Grassi, which occurs in four 

 species of Mus, in Arvicola, in the cat, and in man ; but though often 

 coexisting with a diarrhoeic condition, it does not appear to cause it. 



Fam. 3 includes Lophomonas hlattarum Stein. 



Fam. 4 contains the single species Trichomonas melolonthce Grassi, 

 which appears to assume a great variety of forms when multiplying. 



Fam. 5. Besides Trypanosoma, the family includes a genus Para- 

 mecoides Grassi, containing Trypanosoma Eberthi Kent, and P. costatus, 

 n. sp. from the blood of Rana escidenta ; the genus is distinguished 

 by the presence of an undulating membrane without any trace of a 

 flagellum. 



Class Lohosa. — Grassi thinks his Amoeba ranarum may perhaps 

 "have some relation to Paramecoides costatus, with which it is found 

 associated. 



Amoeba Chcetognathi (= SagittcB Grassi) and pigmentifera n. sp. 

 are found in the six species of Chcetognatha found in the Straits of 

 Messina, chiefly in the caudal chamber and the vasa deferentia, and 

 more rarely in the coelom of the body ; they are not found in young 

 individuals. Pigmentifera is distinguished by a blackish eye-spot, 

 and is only found in two species of Spadella. The endoplasm in 

 both species contains a number of granules, which are considered to 

 be of fatty nature, being stained black by osmic acid, and apjiear to 

 constitute a reserve of nourishment. liei^roduction is effected by 

 modification of the internal structure of the body, resulting in its 

 breaking up into a number of corpuscles containing granules, but 

 still imited by the body-wall of the parent ; when they separate they 

 are flattened bodies 7-lOOOths mm. long, 3-lOOOths broad, and 1-lOOOth 

 thick, and of oval outline ; from one pole proceeds a flagellum of 

 twice the length of the body. Grassi considers that the history of 

 their development tends to approximate the Arnxbce to the Monera, 



