36 



ILLINOIS BIOLOGICAL MONOGRAPHS 



[324 



Since the essential features of the internal anatomy of this species have 

 been worked out by the European workers, only the striking similarities 

 and differences to and from the data given in particular by Kiessling, Fuhr- 

 mann and Solowiow will here be dealt with in support of the writer's contention, 

 in the absence of European material for comparison, that here in America 

 we have the same species as that found in Europe. It will be considered that, 

 as brought out by Liihe in three controversial papers (1897, 1897b, 1899a :7 15) 

 and by Cohn (1898:126, footnote), S. zschokkei Fuhrmann 1898 is synonymous 

 with S. solidus. As a matter of fact many of the data given below will be seen 

 to compare more favorably with those pubUshed by Fuhrmann than with 

 those by either Kiessling or Solowiow. 



According to Kiessling the cuticula is from 15 to 18/i m thickness and divisible 

 into two layers, of which the inner and lighter is from 8 to 9m thick, while 

 the outer is striated or granular. Fuhrmann described a cuticula only 7^ in 

 thickness and divided into two layers, and Solowiow gave the thickness of 

 the "homogeneous cuticula" as 23//. Minckert (1905a :402) said that the 

 comidian or pseudociliated layer, present in many bothriocephalids, was quite 

 evident in S. nodosus but absent on the posterior borders of the proglottides. 

 Here the cuticula was found to be 15ju in thickness, excepting on the posterior 

 borders where it is only Sji, and divisible into two layers, the outer of which, 

 a little thinner than the inner, was much lighter, granular in consistency or 

 somewhat striated with, however, a more or less uniform external boundary. 

 It seems to be easily separated from the inner stratum, the bounding line, in 

 reality the innermost portion of the external layer, being in most places very 

 light. In fact the brightness of this inner layer of the outer stratum indicates 

 the degree of separation of the two layers in the process of sloughing off the 

 outer, which can be easily followed in sections as described by Kiessling. This 

 description however, applies only to the adult stage. In larvae the cuticula, 

 altho of the same thickness, shows an outer decidedly pseudociliated layer only 

 Ay. in depth. The subcuticula, 88.5At in thickness in the median line according 

 to Solowiow, was found to be from 40 to about 65ai, Kiessling having given 

 the limits as from 29 to 38/:x. While the parenchyma is as described by the 



