247 



in the deeper layers of the water with better success than duriug 

 the summer of 1903. With this net were captured an uninter- 

 rupted series of later larval and postlarval stages both oïtrarhinus 

 vipera and of trachimis draco, so that the small fishes could be 

 determined with perfect accuracy. 



As litterature is singularly scarce about the later larval and 

 postlarval stages of Trachinus vipera, and about the same stages 

 of Trachinus draco as far as I could gather, nothing is known ^), 

 I will describe the features of both species here at some length 

 and compare them with each other, as they present some remark- 

 able differences and peculiarities. 



Trachinus vipera. Of the postlarval development of the Lesser 

 weever only some later stages are described by Mc. Intosh and 

 Masterman ^) and Holt '). The smallest specimen described by 

 Mc. Intosh and Masteeman measured about 15 m.M. in length 

 (in spirit) and was taken by the ,,Garland" probably in autumn, 

 but the date is uncertain. Of this specimen the spines on the 

 preoperculum and on the operculum, the position of the fins and 

 the colouring are described, and a dorsal view of it is figured 

 in plate VI, fig. 8. 



The following specimen was measuring 26 m.M. in length, then 

 foliowed an example, 33 m.M. (l^/ie inches) in length, taken by 

 the ,,Garland" in the Dornoch Firth ; this specimen was doubt- 

 less about one year old. 



Mr. Holt describes a larva 13.75 m.M. long, which was very 

 much like the adult. It was taken near Plymouth in september 

 1897, and could easily be determined as a Trachinus vipera by 

 the number of the dorsal and anal finrays. Only black jugment 

 was to be seen (in the preserved specimen), in the foremost part 



1) When I was in Heligoland, Prof. Ehrenbaum had the kindness of showing me a 

 drawing of a larva, which, he thought, might possibly be a Trachinus draco. I think 

 he was right in this surmise. 



2) Mc. Intosh and Masterman. British marine food-fishes, 1897, p. 156 — 160. 



3) E. W. L. Holt. Recherches sur la reproduction des poissons osseux etc. Annalea 

 du Muse'e d'hist. nat. de Marseille, Tomé V, Mem. 2, 1899, p. 33—3 5. 



