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Part III. — Eighteenth Annual Report 



One or two of the cephalo thoracic appendages are represented by- 

 figures 4-8. 



Lernceopoda galei, Kroyer. ( 1. VIII., figs. 16-25.) 



1837. Lernceopoda galei, Kr. 3 Naturh. Tidsskr., r. i., vol. i., p. 272, 

 PI. III., fig. 5. 



1850. Lernaiopoda galei, Baird, op. cit., p. 334, PL XXXV., 

 %. 7. 



A number of specimens of Lernceopoda galei have been obtained on 

 tope (or topers, as the tish is sometimes called), Galeus canis, Rondel. 

 (Galeus vulgaris, Flem.), occasionally brought to the Fish Market at 

 Aberdeen. Specimens have also been sent to me by Mr. Duthie, the 

 fishery officer at Girvan, which he had obtained on topers captured in 

 Clyde waters and landed there. The parasites were most frequently 

 found adhering to the skin beneath and between the ventral fins of male 

 fishes ; it appeared to be less frequent on females. Lernceopoda galei 

 has also been obtained on a male specimen of the lesser spotted dog-fish, 

 Scyllium canicula, caught in the Firth of Clyde, aud on a specimen of 

 the same kind of dog-fish sent from the Moray Firth. This Moray Firth 

 specimen was also a male. 



In this species of Lernceopoda the arms are only moderately elongated ; 

 the body becomes gradually dilated posteriorly, and is truncate at the 

 end. The abdomen is almost obsolete, and is situated between two 

 distinct though short and slender processes which spring from the end of 

 the genital segment. 



The antennules, antennae, and mouth-organs are somewhat similar to 

 those of Lernceopoda elongata. The specimen represented by the drawing- 

 is about 13mm. in length from the forehead to the end of the posterior 

 appendages, and exclusive of the ovisacs and the second maxillipedes. In 

 another specimen, which measured about 14mm., the ovisacs measured 

 fully 9mm., and the posterior appendages about 3mm. 



Lernceopoda bidiscalis, W. F. de Vismes Kane. 



1892. Lernceopoda bidiscalis, W. F. de V. Kane, Proc. Rov. 

 Irish Acad. (3), vol. ii., p. 203, Pis. IX. and X. 



The species described under this name has hitherto been observed only 

 on the male of the tope, Galeus canis. It is found adhering to the ends of 

 the claspers, [and the place where the parasites are attached is almost 

 invariably found to be torn and bleeding. The describer of the species 

 draws attention to this circumstance. I have found it to be almost 

 invariably the case with topers landed at the Fish Market at Aberdeen, 

 and Mr. Duthie, fishery officer at Girvan, finds that male topers caught 

 in the Clyde and landed at that place have also the ends of the claspers 

 torn and bleeding where these parasites were adhering. Whether these 

 wounds are caused directly by the parasites or are produced by the efforts 

 made by the sharks to shake off their tormentors is a question that does 

 not yet appear to have received a satisfactory answer. Usually one, but 

 sometimes two, parasites are found adhering to the same clasper, and on 

 a few occasions we have found two parasites on each of the two claspers 

 of the same fish. The fishes from which the parasites were obtained were 

 chiefly adult males with well-developed claspers ; we have rarely observed 

 this Lernceopod adhering to the claspers of young males. 



The specimens of Lernceopoda bidiscalis observed by us had for the 



