larva these hooks can extend beyond the limits of the attaching disc and 

 apparently it is precisely by them that the larva first attaches to its host. 

 The small edge hooks are located along the edges of the attaching disc and 

 are so small that it is sometimes very difficult to notice them. They have 

 a curved handle and a small point. The average length is 0. 014 - 0.016 

 mm, the length of the point is 0. 005 - 0. 006 mm. In the middle part of 

 the larva one can distinguish the inception of the intestine. " 



Just as his drawings, the description of U. A. Strelkov suffers 

 by an apparent schematization. One must note two instances: first, that 

 his enumeration of the middle hooks is the reverse of that accepted by us, 

 i. e. , the hooks, called by him as the first pair, correspond to our 2nd 

 pair in the preceding descriptions. The second and more substantial cir- 

 cumstance is the fact that Strelkov did not pay any attention to the presence 

 of another pair of eyes lying lower than the double eye represented by him. 

 This error is a result of the fact that glycerin -jelly preparations contain 

 strongly flattened worms. As a result the 2nd pair of eyes happened to be 

 displaced almost to the edges of the body and gave the impression of p. 216 



accumulations of pigment having no relation to eyes. Nevertheless they 

 are undoubtedly eyes, which is confirmed by our data on Axine sp. I and 

 Axine sp. II. The larva of these species of Axine are essentially very 

 similar to that of A. belones Abildgaard (Figs. 259, 260) but differ basically 

 by the fact that the first type has 4 clearly expressed eyes and the 2nd--3, 

 of which the anterior is doubled- -fused- -and has 2 light refracting little 

 lenses, whereas the 2 posterior are of normal structure. In such a fashion 

 the representatives of the genus Axine have 3-4 eyes in the larval stage 

 which completely disappear in the subsequent developnnent (see page 402 ). 



29. The development of Diplasiocotyle Sandars 



In 1944 Sandars (Sandars) described a new species and genus 

 of Microcotylidae from the gills of Agonostomus forsteri Cuv. and Val. 

 from western Australia. According to the author this genus is charac- 

 terized by differences in the structure of the attaching disc. It bears 

 only 7 pairs of relatively large clamps and one small terminal (pair of 

 clamps, nobis). Unfortunately we were not able to obtain the original 

 work of the author and because of that have no way to judge the propriety 

 of the establishment of this genus. The development of the given species is 

 described in this work (I ann indicating this according to the data which were 

 cited in the resume of Sproston). The larvae emerge on the 19th day after 

 the deposition of eggs. They bear a ciliary covering which is located in 

 three zones just as among Microcotyle. They resemble the larva of M. 

 spinicirrus and have 2 pairs of middle hooks and 3 pairs of edge hooks on 

 the attaching disc. The youngest worms discovered on the gills of the 

 host have the length of 0. 687 mm and a well-developed attaching disc 

 having a diameter of 0. 312 mm. The disc bears 4 pairs of attaching 



235 



