Some Points on the General Auatoiny of Gyrocotyle. 725 



1. The acetabular or cephalic cone (Kopfzapfen). 



2. The main visceral mass. 



3. The lateral frills or ruffles. 



4. The terminal rosette. 



Tlie cephalic cone is the only region which is not egually dis- 

 tinct in all specimens. Under conditions of extreme contractiön 

 (Fig. 7) it all bat disappears in the general mass of the body altho 

 ander otlier conditions it is easily distinguished or even conspicuonsly 

 marked oft' from the rest. In general this cephalic cone may be 

 described as the acetabnlar tip of the body, the proximal bonndaiy 

 of which is indicated by the furrow which has been called the 

 genital notcli (Fig. 8). This furrow lies at the point where the 

 lateral folds begin. It is not always distinct and yet is not merely 

 an asymmetrical indentation of one margin as indicated by Watson. 

 The cephalic cone (Fig. 5) when fullj^ extended measures 5 mm in 

 lenght or more. It is mobile, like the corresponding region in flukes. 

 and may be reflexed so far as to stand nearly parallel to the main 

 mass of the body. On either side it tapers to a sharp ridge which 

 appears in lateral aspect like a line (Fig. 6). This region is entirely 

 devoid of the lateral ruffles which characterize the main body mass 

 and have their anterior termination at the genital furrow. Along 

 the sides of the anterior cone are seen sparsely scattered spines. 

 They are located usually near the ridge and are wanting over the 

 general dorsal and ventral surface of the cone. By reason of this 

 limited distribution they appear in highly contracted specimens as 

 "cheek patches" (Fig. 8), right and left of the acetabulum. in which 

 the spines owing to the contractiön are so closely set that they 

 constitute gray dotted areas of a conspicuous type. This feature so 

 characteristic in the anterior aspect of the animal appears to have 

 passed unnoticed at the hands of some investigators altho noted and 

 figured by Wagenee. 



The genital notch, so-called, or better the furrow which sepa- 

 rates the anterior cone from the general body mass is fairly distinct 

 in specimens representing all degrees of contractiön. It appears not 

 merely on one margin but on both and varies only in tlie depth 

 and distinctness it possesses in different individuals. Two of the 

 external orifices of the body are not in the notch but at least close 

 to it altho by no means always so distinct as to make their deter- 

 mination an easy matter. 



Extendiuo- along- either side from the genital furrow to the 



