156 RESEAKCHK.S IN HELMINTHOLOGY AND PARASITOLOGY. 



parasite of the shrimp, Pahemonetcs vulgaris, which he recognized 

 as the curious Isopod, liopyrus. Many of the shrimps were infested 

 with the parasite, the presence of which produced a conspicuous 

 hemispherical tumor on one side of the carapace. 



[October, 1879. No. 477. See Bibliography.] 



On Amoeba Blatta\ — Prof. Leidy remarked that while perusing 

 the communication of Prof. Biitschli on " Flagellata and other re- 

 lated organisms" (Beitrage zAir Kenntniss der Flagellaten und 

 einiger verwandten Organismen), in the Zeitschrift fiir wissenschaft- 

 liche Zoologie, 1878, 205, his attention was especially attracted by 

 the description of a parasitic amoeboid liv'ing in the intestine of the 

 cockroach, Blatta orioitalis. It recalled to mind that he had ob- 

 served the same creature a number of years ago in association with 

 the ciliated infusorian he had described as Nydotherus ovalis. At 

 that time he had viewed it as a young form of a Gregarina, and had 

 intended giving it and other parasites of the cockroach more critical 

 examination, but failed to do so. The parasitic Arnoeha blattce is 

 particularly interesting on account of its habit and its peculiar char- 

 acter. Prof. L. had recently examined some cockroaches, and found 

 abundance of the amoeboid in association with Nyctothcyus ovalis, 

 Lopho77ionas blaftaniui, Oxyurus gracilis, and O. appendiiiilaliis and 

 an algoid plant. 



The amoeboid, he thought, was worth}' of a generic distinction 

 from the true Amoeba, holding a position between this and Prol- 

 amoeba. From the former it differed in the absence of a contractile 

 vesicle and, commonly, also of vacuoles, and in the want of differ- 

 entiation of endosarc and ectosarc, and from the latter in the posses- 

 sion of a well-defined nucleus. He propo.sed for it the following 

 name, with distinctive characters : 



Endamoeba. — General character and habit of . hiiocba ; composed 

 of colorless, homogeneous, granular protoplasm in the ordinary 

 normal, active condition, without distiction of ectosarc and endo.sarc ; 

 with a distinct nucleated nucleus, but ordinarily with neither con- 

 tractile vesicle nor vacuoles. 



Endamoeba Blattce. — Eine art Proteus. Seibold : Beitr. z. Nat- 

 urges, d. wirb. Thiere. 1839, fide Stein. 



Amobenform. Stein: Organismus d. Infusionstheire, 1867, II., 



345- 



Amoeba Blattce. Biitschli: Zeits. f. wis. Zoologie, 1878, xxx, 273, 

 Taf. , XV, Fig. 26. 



Initial form globular, passing into spheroidal, oval, or variouslj' 



