EGGS AND LARVAE OF TELEOSTEANS. 115 



Eggs taken by the tow-net at Newport, identified as belonging to Motella 

 argentea, are described by Agassiz and Whitman in Pelagic Stages of Young 

 Fishes. The identification is based on the character and distribution of the 

 pigment in the larva hatched from the eggs, and is to some extent doubtful. 

 The average size of the eggs is *78 mm. There is a single oil globule (in one 

 case two, which coalesced) which is large and colourless, and measures '15 to 

 •16 mm. in diameter. The figure given of the newly-hatched larva agrees 

 closely with Brook's figure of Motella mustela. The embryonic period varied 

 with the temperature from three to six days. The eggs were taken from May 

 to July. 



Motella cirnbria, Nilsson (Linn.). — The four-bearded rockling. Parnell's 

 example, captured in June, had the ova almost mature. Three specimens 

 were taken by me, in the trawl, off Fast Castle Point, Haddingtonshire, March 

 12, 1886. In these the reproductive organs were very small. The largest 

 specimen was '26 m. long. 



A species allied to Motella, probably actually a species of that genus, is 

 figured in Pelagic Stages, pi. xii. The ovum is "70 mm. in diameter, and has 

 a single oil-globule. The newly hatched larva agrees with that of Motella 

 mustela, in that the rectum terminates, apparently blindly, immediately behind 

 the yolk, and does not extend to the edge of the ventral fin-fold. The eggs 

 were obtained in March and April. Another species allied to Motella is 

 figured in Pelagic Stages, plate ii. figs. 1 to 3. 



The ovum of Merlucius is mentioned and figured by Kingsley and Conn,* 

 but the size is not stated. Like that of Motella, it has a single large oil 

 globule at the vitelline pole. 



The eggs and larvae of Lota vulgaris, the burbot, have been described by 

 Carl J. Sundevall in Svenska Vetensk. Akad. Hand., 1855. The species is 

 entirely confined to fresh water, and is thus unique among the Gadidse, all the 

 rest of which are marine and produce pelagic ova. The ova of Lota are shed 

 separate and loose at the bottom of the water ; some ova are opaque, some 

 transparent. According to Sundevall, they are small, but measurements are 

 not given. Figures of the newly hatched larva and somewhat later stages are 

 given ; the drawings are not quite adequate, but show some essential points. 

 In the newly hatched larva there is a single oil globule in the yolk, and there- 

 fore probably in the ovum ; the anus is close behind the yolk, but not in contact 

 with it ; the larva is 3 mm. in length. This larva bears a close resemblance to 

 that of Motella, as figured by Brook. There are two differences in Lota ; the 

 oil globule is not so far back, and the two transverse stripes of pigment in the 

 tail of Motella are wanting. The pigment in an eight days old larva of Lota 



* Memoirs of Boston Society of Natural History, vol. iii. No. 6, 1883. 



