330 MR. R. COLLETT ON CERTAIN GOBIOID FISHES. [Mar. 5, 



large swimming-bladder, which occupies a considerable part of the 

 belly, expands still further when the individuals are brought up 

 to the surface, the somewhat fatigued fish not being able to com- 

 press it so as to make the specific weight of the body to decrease 

 sufficiently to permit it again to descend under the water. The 

 weight of the body is also diminished by the loss of the scales ; 

 consequently a great number of such individuals are driven about 

 on the surface of the water in a still living state, till they are 

 carried away by the stream or picked up by sea-birds and other 

 enemies. They swim, however, not without a certain degree of 

 rapidity. 



Their enemies are almost all other fishes who occupy the same 

 locality. Especially the different kinds of Gadus devour large masses ; 

 and even in the case of small specimens of Gadus morrhua, G. 

 esmarkii, and G. merlangus, I have occasionally found the stomach 

 crammed with them. "When they float about in their helpless state 

 on the surface of the water, Gasterosteus aculeatus and Spinachia 

 vulgaris snatch large pieces out of their brittle bodies. 



As mentioned above, their food consists chiefly of microscopic 

 copepoda and other small pelagic animals. In the specimens that I 

 have examined in the Christiania Fjord, tbese principally consisted of 

 the copepods Dias longiremis, Lilljeb., Temora velox, Baird, together 

 with the larvae of decapods {Hippolyte and Palcemon), and mollusks 

 in their swimming- stage {Cardium). The stomach contains this 

 kind of food both in the summer and the winter. 



Distribution. — Taking for granted, that the forms from Southern, 

 Western, and Northern Europe are identical, L. peflucidus has a very 

 wide distribution, although our information touching this species is 

 at present very incomplete. In this case it is met with (possibly in 

 certain spots only) from the western coast of Norway, about 60° N. 

 long., down along Western Europe to the Mediterranean, in the 

 Adriatic, and right up to the innermost parts of the Black Sea. 



In Norway it is met with outside of Bergen, and in tbe Christi- 

 ania Ejord. At the first-named place the late naturalist Mr. Stuwitz 

 obtained four specimens in December 1 S34 ; it has, however, not since 

 been found in this locality. In the Christiania Fjord I have found 

 it in several places inside Doobak, chiefly amongst tbe islands outside 

 Christiania ; most likely it is to be found in the outer parts of the 

 fjord also, and undoubtedly at other places along our southern coast, 

 not mentioned here. 



In Sweden it has been found by Dr. Malm in Bohuslen. 



In Scotland Mr. Parnell has taken it in Solway Frith, June 1 836 ; 

 and in his ' Catalogue ' Dr. Giinther states that the British Museum 

 also has specimens from the Frith of Forth. 



In the Mediterranean it is known, through Prof. Canestrini, from 

 the Gulf of Genoa; and Prof. G. O. Sars found it in the beginning 

 of 1876 at most of the places visited by him — e. g. in Sicily, at 

 Messina, and Syracuse — everywhere in enormous masses. In the 

 Adriatic, whence it was already described in 1824 by Nardo, and 

 afterwards mentioned by several authors, be found it at Trieste. 



