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types of sinistral ZeiKjopfrruit larvæ, tlie smootli and tlic spiny one, it is, 

 a priori, the most uatural thing to suppose that they must belong to the 

 two species of Zeugopterus whicli live in our seas, viz. Z. norvegicus and 

 Z. pimdatHS. For our seas have been so tlioroughly investigated with all 

 kinds of tishiug-gear, that I have uo hesitation in sayiug that ueitlier Z. 

 unimaculatus nor Z. megastoma can have been overlooked within the Skaw, 

 if they really have their home here. On the other hånd, the possibility is 

 not excluded, of course, that small youug ones of these species can be 

 carried into the Cattegat by currents. I know that this is tlie case with 

 many other organisms. But here such a supposition is not very probable; 

 more particularly because Z. megastoma is a deep-sea form, and Z. unima- 

 culatus is not known in the seas nearest to Denmark. I suppose therefore 

 that the two types of Zeugopterus larvæ must be referred to the two species 

 that are found in our seas, viz. Z. norvegicus and Z. punctattis. Z. unimaculata 

 is out of the questiou, with us as well as in Scotland, ouly in Danmark 

 with greater certainty; for the rocky shores of Scotland eau more easily hide 

 it than our sandy beaches. 



At this point my investigations have remained for a long time, as I 

 was unable to prove to which of the two Danish species the smooth larvæ 

 were to be referred, and to which the spiny ones. By the kindness of 

 Collett and Holt I have now overcome this difficulty. Among the young 

 fish of the genus Zeugopteyus which Holt sent me from Ireland, was the 

 only 9,5 mm long specimen of which a picture is given ou table I, tig. 5. 

 It was cauglit near the bottom, June 11., 1901, and evideutly belougs to a 

 very late larval stage, whose pectoral fins, however, are not yet fully devel- 

 oped. In its pigmentation it resembles much the 13 mm long specimen of 

 Z. pnnctatus of which I, sometime, gave a picture in ''Report IV", tig. 15; 

 it was sent to me by Collett, who himself correctly considered it to be a 

 young Z. pnnctatus. Holt's 9,5 mm long specimen had uo spines on its 

 head, but a rouuded protuberance over the ear-rcgion, on whicli tiiey might 

 very well have been placed. This specimen of Holt's also appears to belong 

 to Z. puncfatus by the whole form of its body, its lower jaw, the form of 

 its dorsal and anall tins, its small and short caudal tin, and finally, its num- 

 ber of rays, vi/,., d. about 95, a. about 69. But besides that it reminds you, 

 on the other hånd, of such forms as those of which M'Intosh and Master- 

 mann in "Food-tishes", pi. XIV, tig. 8, have given us pictures, and of which 

 Holt has sent me a specimen from Valencia in Ireland, cauglit Oct. 12., 1897. 

 Éy means of Holt's, I am sorry to say greatly damaged specimen, c. 10 mm 

 long, with c. 98 dorsal and c. 73 anal rays, with distiuct pairs of sjiines 

 on, and of fig. 8 in "Food-fishes", I have drawn my lig. 4, table I. This 

 figure, drawn from M'Intosh's fig. 8, with c. 87 d. and c. 62 a., and 

 from Holt's above mentioned specimen, which were, both of them, spiny, is 

 in the form of its lower jaw and of its tail, in leugth and pigmentation, 

 very like my fig. 5; only with such alterations as may easily be explained 



