STUDIES OX THE ECTOPAEASITIC TfifiMATODES OF JAPAN*. 109 



the female duct by its constunt form ; but in Microcotyle, Azine, 

 Octocotyle, Diclidophora, Hexacotyle, and Onclwcotyle, it can not be dis- 

 tinguished superficially from the other parts unless during the period 

 of reproductive activity. It is, however, usually well characterised by 

 the fact of its receiving the openings of numerous unicellular shell- 

 glands either throughout its whole extent, as in Axine, Microcotyle, 

 Octocotyle, Diclidophora, Oiicliocotyle, and Hexacotyle ; or, as in 

 Tristomum, Epibdella, Calicotyle, and Monocotyle, only at the beginning 

 of the ootyp. In most genera of the first group the shell-glands ai'e 

 situated only around the ootyp ; but in most species of Microcotyle 

 they are present not only around the ootyp but also at some distance 

 behind it (PI. IV", fig. 4), so that those that are far removed 

 from the ootyp come to be provided with long efl:erent ducts, which 

 then open close to each other at the very beginning of the ootyp. 

 When the glands are active these efferent ducts are filled with a 

 granular substance, evidently the product of secretion, which stains 

 deeply with haematoxylin (PL IV, fig. 4). It is undoubtedl}'- these 

 ducts which Lorenz'^ has described as the " Quaste." In Microco- 

 tyle the shell-glands form, moreover, a compact mass around the 

 ootyp, which looks usually triangular in cross-section (Pi. IV, fig. 8), 

 owing to the pressure of the neighbouring organs. In other case, 

 where the glands are free from any pressure, they are arranged almost 

 uniformly on all sides of the. ootyp, as in Axine, Hexacotyle, Octocotyle, 

 and Diclidophora. 



In Onclwcotyle the shell-glands are divided into four groups 

 owing to the intervention of other organs (PI. XVI, fig. 3). There 

 are two groups on the dorsal side and two on the ventral side of the 

 body, the groups on the same side baing separated from each other in 



1). Lorenz — XJeber die Organisation der Gatt. Axine n. Microcotyle. Wiener Arbeiten, 

 Bd. 1, 1878. p. 17 & 27. 



