PolythnJami'an from Transijlo'inia. 359 



least tliroughout the poljthalamous Imperfoi-ata and a g-reat 

 part of the simple Pevtbrata. In the more highly developed 

 forms of the latter division the septum, however, is strength- 

 ened by the wall of the new chamber taking part in its 

 formation " *. In accordance with this Entzia cannot possibly 

 be referred to the Imperforata, but it represents a form which, 

 in consequence of the absence of pores and the structure of 

 the septa, unites the two main groups, but nevertheless 

 approaches more closely to the Perforata than to the Iniper- 

 forata. 



Let us now take into consideration the composition of the 

 shell-walls and their apertures, and compare Eatzia in this 

 direction with the Perforata. In characterizing the LagenidaB, 

 Carp., Biitschli says, amongst otlier things : — •" Aperture 

 usually characteristic, somewhat tubularly produced " f, 

 while of the group Globigerinie, Carp., he remarks, " Aper- 

 ture, in opposition to the Lagenidge, usually fissure-like, and 

 not tubularly produced "J. In accordance with this, our 

 genus, by virtue of the structure of its septa, certainly very 

 closely approaches the subfamily Kotalinae in the group 

 Globigerinffi, but is sharply distinguished by its tubularly 

 produced aperture, whilst in this respect it approaches tlie 

 Lagenidte, from which again it is distinguished by its septa 

 possessing not a single aperture, but four of them, and, indeed, 

 two larger oval ones and two smaller round ones, a case 

 which, so far as I know, is quite isolated. 



As regards the constitution of the shell, we have already 

 shown that in our Polj'thalamiau it consists of a chitinous 

 foundation-substance which is impregnated with silica; this 

 foundation-substance further contains angular siliceous plates 

 of various forms and sizes. A similar constitution of the shell 

 is, indeed, known in many Mono- and Poly thalamia ,• but the 

 composition of chitine and silica reminds one vividly of the 

 Difflugice and allied Rhizopoda generally of fresh water. In 

 this respect, indeed, our Polythalamian certainly comes near 

 .Poh/morphiiia siliceaj oii which Max Schultze savs : — "The 

 sliell is of a yellowish colour, characterized by numerous very 

 irregular depressions, which do not perforate it, and consists,' 

 at least for the most part, of silica " § ; but the shell of Poli/- 

 morphina also seems to contain some lime, as indicated by 

 Max Schultze's statement, " The quantity of calcareous salts 

 that may be present with the silica can only be very small," 

 &c. But with all this it cannot be saiil that Entzia^ as regards 

 the substance and structure of its shell, is far removed from 

 * Loc. cit. p. 45. t Loc. cit. p. 197. 



X Loc. cit. p. 200. § Loc. cit. p. 61, 



