l8 THE AMOEBAE LIVING IN MAN 



Entamoeba Casagrandi et Barbagallo, 1895 ; whilst provisionally I reserve 

 the separate genus Endamoeba Leidy, 1879, tor the amoeba of the 

 cockroach. On this system, the type species of Entamoeba is £. colif 

 and the type of Endamoeba is E. blattae. They have not one common 



type- 



I may perhaps remark here that although it is clearly incorrect to 

 attribute to any authority a name which he did not employ, this has 

 frequently been done in the case of the names under discussion.* For 

 example, I note that Craig (1912, Lgi2 a) writes " Entameba Casagrandi 

 and Barbagallo" ; later (Craig, 19 13 6, 1914) "Entamoeba Leidy" ; still 

 later (Craig, 1917) " Endameba Leidy." Not one of these is the name 

 employed by the authority cited. Moreover, I would protest against the 

 suppression of the diphthongs in Amoeba, Entamoeba, and Endamoeba, 

 which has now become habitual with most American writers. They 

 may be justified in translating the English word " amoeba " into the 

 American "ameba" (plural, " amebas ") : but it is difficult to see what 

 grounds they can have for altering the Latin language— for generic 

 names like " Entamoeba " are, theoretically at least, Latin and not 

 American. For my part, I find "Endameba" almost as unpleasant as 

 the quite unjustifiable and offensive "Entamoba "which German writers 

 frequently employ. Obviously, "Amoeba" (and all derivatives such as 

 Entamoeba or Endamoeba) is orthographically correct as a generic name 

 only when written thus in its original form. 



In addition to the three amoebae belonging to the genus Entamoeba 

 there are three other species which have to be noted here. First, there 

 is the organism named Entamoeba nana by Wenyon and O'Connor 

 (1917). This organism clearly belongs to a different genus from that 

 typified by E. coli. From examination of the evidence I consider that 

 it should be placed in the genus Endolimax Kuenen et Swellengrebel 

 (1917). This question will be considered in greater detail, however, in 

 the discussion of the nomenclature of this species, {Vide infra, p. loi.) 

 Secondly, there is the peculiar binucleate amoeba for which — in a joint 

 paperf — I have proposed the name Dientamoeba. The nomenclature of 

 this organism has already been discussed in detail in the earlier paper. 

 Thirdly, there is another intestinal organism which is described in the 

 present work, but which has previously been known in a disconnected 

 and incomplete manner. This is the organism called Entamoeba biltschlii 

 by Prowazek (i9i2«), but whose cysts were called "Iodine cysts" by 

 Wenyon (1916). As this amoeba cannot be placed in any of the existent 

 genera, I shall propose the new genus lodamoeba for it. The nomen- 

 clature of this organism will be discussed later, in the description of 

 the species. 



In the next section I shall attempt to give a systematic account of all 

 the species of amoebae from man. Before doing so, however, I may 

 summarize the conclusions reached in this section. They are set forth 

 in the following synopsis, which will show the genera, species, and 

 types at a glance, and will also serve as a key to the species described in 



* In addition to the instances cited I may also note that Hartmann (1913) writes 

 " Entamoeba Leidy emend. Schaudinn " — a remarkable combination when it is 

 remembered that Leidy's real name {Endajnoebd) was unknown to Schaudinn, who 

 used Entamoeba Casagrandi et Barbagallo. 



t Vide Jepps and D obeli (19 18). 



