this, Cerfontaine (Cerfontaine, 1895c) showed that in D. denticulata 



(Olsson) the vagina is precisely the same type as the one described for 

 Echinopelma (see Raecke, 1945). It is also possible that the genus 

 Choricotyle or its separate species likewise have a small vagina leading 

 from the receptaculum seminis, and then perhaps the proximity of 

 Echinopelma and Chorico tyle will appear to be even more considerable. 

 This is made more probable because of the fact that Echinopelma was 

 described with insufficient accuracy. Thus, in spite of a rather detailed 

 representation of the ducts of the sex system in E. bermudae Raecke, the 

 ductus genito-intestinalis , which undoubtedly exists, was not shown. 



5. Family Microcotylidae Taschenberg, 1879 



(Figs. 8, 9, 23, 40, 60, 66, 75, 78, 93, 105, 113, G, 

 H, 125, 235-260, 308, 309) 



Discocotylinea, middle or large sizes. The attaching apparatus 

 consists of 2-3 pairs of hooks which can be absent among adult forms and of 

 numerous (more than 4 pairs) clamps of the discocotylid-type. Usually there 

 are one pair of edge and 2 pairs of middle hooks. More seldom the latter are 

 represented by one pair. The attaching clamps are located on a more or 

 less separated disc or along the edge of the body, sometimes extending 

 anteriorly above the level of the ovary. As a rule the clamps lie symmetri- 

 cally along the edges of the disc and their number is more or less equal on 

 both sides, more seldom their number is considerably larger on Qie side 

 than on the other and finally they can be located in one asymmetric row in 

 relation to the axis of the body. The sizes of the clamps vary; usually the 

 largest clamps are in the middle of their row. The anterior end has more 

 or less developed cephalic glands lying in three groups. The buccal cavity 

 has relatively powerful suckers. The intestinal trunk is two-branched. Its 

 branches merge with each other at the posterior end of the body forming 

 more or less numerous lateral and internal outgrowths and internal anasto- 

 moses along its length. The male sex aperture and the aperture of the uterus 

 open for the most part into a common sex atrium. The latter is often 

 armed by a different number of small chitinous hooks. The copulatory 

 organ is armed or unarmed. As a rule the testes are follicular, numerous; 

 the ovary is flask-shaped and usually curved into the S or reversed R 

 (perhaps? U-shaped) shape. Vaginal ducts exist, more rarely they are 

 absent. Their openings are either single or more seldom double, they lie 

 on the dorsal side below the level of the sex opening. The uterus is pipe- 

 shaped or often sac-shaped and as a rule contains a large number of eggs, 

 more seldom it contains one egg at a time. 



Parasites of marine (as an exception fresh water) fishes. 

 Basically encountered on Perciformes and more seldom on Beloniformes, 

 Mugiliformes, and Polynemiformes. 



525 



