278 Part III. — Twenty-second Annual Report 



more common Lemma branchialis, and hitherto it appears only to have 

 been observed on the gills of the Brassie or Whiting Pout (Gadus luscus, 

 Linn.). The specimen I have to record was obtained on the gills of a 

 Brassie captured about ten miles off Aberdeen on January 16, 1901. 

 This parasite measures a little over half an inch from the head to the end 

 of the genital segment. The neck is slender and short, and the append- 

 ages of the cephalon are moderately developed. Dr. Bassett-Smith 

 describes the posterior appendage as being sometimes as long as the neck, 

 which is also characteristic of the specimen now recorded (fig. 13). The 

 genital segment is considerably dilated and strongly sigmoid, except at 

 the posterior end where, in marked contrast to Lemxa branchialis, it is 

 only slightly curved ; the twisted egg sacs are proportionally not so slender 

 as in that species. 



Lemcea lusci does not appear to have hitherto been recorded from 

 Scottish waters, having been probably regarded as a form of L. branchialis. 

 Figure 1 2 shows the specimen attached to the gill-arch of the fish. 



Brachieila pastinacce, Van Beneden. 



1851. Brachieila pastinacce, Van Beneden, Ann. des. Sci. Nat., 

 3rd ser., t. xvi., p. 118, pi. iv., figs. 8, 9. 



Two specimens of this Brachieila were obtained in the nasal fossae of 

 the Trygon in which the Eudactylina just described was found. One 

 specimen occurred in each of the two fossae. These two specimens which 

 were posted to the artist along with a few other things in order to have 

 drawings of them prepared, failed to reach their destination, and I am there- 

 fore unable to furnish figures of this species. 



PART II.— TREMATODA. 

 Fam. Tristomatid^e. 



Thaumatocotyle concinna, gen. et. sp. no v. PI. xvii., fig. 15. 



A large sucker-disc, so characteristic of several of the Trematoda, is 

 attached to the distal end of the body by a very short stalk which is 

 apparently flexible. The sucker is nearly circular in outline, and its ventral 

 surface is divided into thirteen marginal compartments which are separated 

 from each other by narrow muscular bands ; the compartment at the lower 

 end of the sucker is larger than any of the other twelve and is of the 

 form of an equilateral triangle, the blunted apex of which is directed 

 inwards and reaches fully half way toward the centre of the sucker ; the 

 other twelve marginal compartments are of nearly equal size and are sub- 

 quadrate in form, as shown in the drawing (fig. 15). Two moderately 

 slender rods spring from two adjacent muscular bands near the centre of 

 the disc, and extending to the circumference of the sucker terminate in 

 little hook-like processes — one on each side of the lower triangular 

 compartment. 



The anterior end, which terminates somewhat abruptly and has a broadly 

 triangular outline, is bifurcated in the middle. On the ventral aspect, 

 close to the margin on each side of the fork and extending from it to the 

 outer angle, there are arranged three small discs which may probably 

 function as suckers. 



The length of the specimen represented by the figure is about 3 milli- 

 metres (nearly | of an inch), while the breadth at the widest part is 

 equal to about one fifth of the length ; the body is flattened and in some 

 specimens nearly transparent, so that the internal structure may to some 

 extent be discovered. 



