of the Fishery Board for Scotland. 279 
This Trematode does not agree with any genus or species known to me. 
Habitat —In the nasal fosse of Trygon pastinaca, captured in Dornoch 
Firth, October 1903. : 
Heterocotyle pastinace, gen. et sp. nov. Pl. xvii, fig. 14. 
Several specimens of the Trematode described under this name were 
obtained on the same Trygon pastinaca with the form just recorded, but 
they were found nof in the nasal fosse but on the gills along with 
Eudactylina minuta described in the first part of this paper. 
In this Trematode the posterior sucker is slightly oval in outline—the 
transverse diameter being greater than that which is longitudinal in the 
proportion of about 13 to 11. The edge of the sucker is indistinctly 
crenate, and its ventral surface is divided into eight compartments, which 
extend from the circumference to near the middle, where they are 
interrupted by a small diamond-shaped space representing the point of 
attachment of the sucker to the body. The two lowest compartments are 
of a slightly larger size than the four upper ones, but the compartment on 
each side is about double the size of the one immediately above. More- 
over, these side compartments, together with the two lower ones situated 
between them, are eavh sub-divided into two portions by a circular line, 
as shown in the drawing (fig. 14). About the middle of the band which 
divides each large lateral compartment from the lower one, there is 
attached a short rod that terminates in a strong hook. ; 
The body is of a narrow ovate form and is considerably depressed ; the 
greatest width is equal to nearly three and a half times the length ; 
the total length of the specimen represented by the drawing is only 
1°44 mm. (about =4 of an inch). The anterior end is narrowly truncate, 
and is without any lateral appendages, as in Phyllonella or Placunella, 
which it otherwise resembles. 
Besides the occurrence of the four different kinds of parasites from 
the Sting Ray mentioned here, Prof. van Beneden has obtained on 
specimens of the same species of fish taken on the coasts of Belgium, not 
only the Brachiella pastinace—which he found both in the nasal fossze 
and on the gills—but also Lerneopoda galei and Ergasilina robusta ; the 
first he obtained in the nasal fossee and the other on the gills. The same 
writer also records finding five different kinds of Cestoids in the 
intestines of Zr-ygon.* 
PART -EEE, 
Note on A Post-LarvaL Fish ATTACKED BY PODON LEUCKARTI. 
Plate X VII.—Fig. 16. 
It is fairly well known to students of the Entomostraca that these 
organisms live to some extent on animal as well as on vegetable matter, 
and also that they do not always confine themselves to decaying sub- 
stances, but that living specimens, if small enough and in a 
weak or sickly condition, are not exempted from being attacked by 
them. When examining a gathering of living Entomostraca in whicr 
Ostracoda are frequent, we may occasionally observe a number of these 
minute Crustaceans crowding round some object of general interest, anu, 
when the reason for the crowding is investigated, find that they are busy 
feeding on a dead or dying companion. 
hi des cotes de Belgique leurs Parasites et leurs Commenceaux, pp. 14, 
