144 



s. GOTO. 



evao-'mafce:], und the spines serve to assist the act of copulation. 



After what have been said above I beUeve it is hardly necessary 

 to point out that the description of the "Cirrus" by Lorenz'Mn 

 Axine hclones seems to me not to correspond to the actual relation of 

 thino-s. I also venture to believe that what has been described by the 

 same writer as the male genital opening in MicrocotijJc mormijri is in 

 re:dity the opening of the genital atrium, and the assumed female pore 

 to be the opening of the uterus not to the exterior but into the genital 

 atrium. 



Tlie spines that are present on the internal surface of the genitMl 

 atriam in Microcotijlc and Axinc I shall call atrial spines to distingui^sh 

 them from the penis spines or hooks of Octocotijle and iJicIidopliora 

 and from the tubular chitinons penis of CalicoUjlc and Monocotijle. 



10. General Considerations and Comparison of Bes^dts. 



I shall now add, ])artly by way of recapitulation, some general 

 considerations; and in the first place I shall discuss — 



1. The Nature of tliose prismatic, refractive Fibres which constitute tlie 

 Wall of the Suchers of Axine, Microcotijle, Octocotijle, Diclidophora, Hexa- 

 cotijle and Oncliocotijle. These fibres have keen spoken of by most writers 

 simply as muscular fibres; the only exception being, so far as I know, 

 AYriirht and Macallum, who sav,"^ "Instead of the substance of 

 the sucker being formed of muscular filtres disposed in tlu'ce directions, 

 and capalile of modifying the shape of the cavity, as in the distomes, 

 it is not possessed of contractility in SphiprDiura (and probably in 

 Pohjstomum), and is formed of prismatic fibres, rather of a supportive 

 than of a muscular character, arranged perpendicularly between the 

 concave and convex limiting membranes of tlie sucker." My observa- 



1). Lorenz— 7. c. pp. 11 & 25. 



2). Wright & Macallum—/. c. p. 12. 



