framework on the periphery 

 its depth. 



of the clamp for opening and also controlling 



HInm] 



Fig. 293. Chimaericola leptogaster Fig. 294. Chimaericola leptogaster 



(Leuckart), attaching disc of an adult (Leuckart), artifically unfolded clamp, 



wornn from the gills of Chimaera The musculature is represented by 



monstrosa L. from the Norwegian cross-hatchings. 

 Sea near the Island of Sere. 



Without speaking for the time being about the peculiarities of 

 the "parentheses" we shall indicate that they are undoubtedly very resilient 

 formations (we have verified this by direct experiments on other species of p_ 413 

 Oligonchoinea), which seek to straighten themselves out, it is true within 

 the limits of their normal curvature, so to speak. Hence, it is clear that 

 the movement of the clamp, as has already been said before (see page 31), 

 takes place during closing with the help of musculature which draws the 

 valves together and which bends the "parentheses" and during the opening, 

 thanks to the resilience of the latter, returning to their initial state and 

 at the same time moving the valves apart. All in all, the chitinous parentheses 

 have a double function --moving and supporting at the same time. As regards 

 the latter function, in addition to "parentheses" it is also borne by the thin 

 subcuticular membrane delimiting the clamp both from the exterior (the 

 thinner) just as from the interior (thicker) sides and forming a noticeable 

 cross-hatching of the surface of the clamps similar to the one in Diclybothriidae 

 (Bychowsky and Gussew, 1950) but more tender. This subcuticular lining 

 of the interior surface of the clamps forms a clearly noticeable edge seam 

 which in preparations produces an impression as if it were lying under the 

 muscular lobes. Along with this, on the anterior valve this seam forms 

 three furrows, one of which extends to the posterior end of the middle 

 "parenthesis" and two lie approximately along the middle of each half of 

 the posterior lobe of the musculature. Similarly, also, on the anterior 

 valve there is a larger seam into which enters the anterior end of the 



494 



