RAPPORTS. XIII C 1 et 3, Appendice — 4 — ' EGGS OF FISHES 



ß. Oil-globules always isolated, less numerous (12 — 15). Egg small: 0.69 

 to 0.94 (VI: 0.84, VII: 0.80). Spawning-time IV to VIII. 



Southern North Sea, Channel. Solea lutea Bp. 



b. Yolk unsegmented ; oil-globules only numerous in the earliest developmental 



stage, fused later to 1, 2 or 3. Chorion almost always covered with an 



air-vesicle; gadoid anus. 



Diameter of egg : 0.66 to 0.98. Spawning-time : II to VIII. (See II B §§ ai). 



Genus Onos Risso. 

 II. Oil in the form of a single globule, more rarely one large with several small globules. 

 A. Yolk segmented. 



a. Segmentation restricted to the marginal zone. Anus not far from the yolk-sac. 



Diameter of egg: 0.81—0.91 (VI: 0.87). Oil-globule 0.23-0.25, in the 

 anterior end of the yolk. Spawning-time VI, VII. 



Southern North Sea. Mullus surmuletus L. 



b. Segmentation total. 



1. Egg with large perivitelline space. Clupeid anus. 



Diameter of egg: 1.50 to 1.80, yolk: 0.80 to O.95, oil-globule 0.16. 

 Spawning-time VII to X, earlier in the Mediterranean. 



Channel, Atlantic south of Ireland. Clupea pilchardus Walb. 



2. Eggs without large perivitelline space. 



a. Egg with transparent gelatinous covering of 0.22 to 0.25 mm. in thick- 

 ness, the surface of which has hexagonal markings drawn out into 

 numerous points. Anus about the middle of the body. 



Diameter of egg: 1.35 to 1.63 (VI: 1.45). Yolk 0.91 to 1.01 ; oil- 

 globule 0.22—0.28, sometimes oval. Spawning-time: IV to VII. 

 Skager Rak, Atlantic. 



Scopelid species, probably Myctophum. glaciale Reinh. 

 ß. Eggs without gelatinous covering. 



aa. Yolk divided by the segmentation into polyhedra. Anus behind the 

 middle of the body. 

 Diameter of egg: 0.81 to 1.04 (VI: 0.93, VII: 0.91). Oil-globule 

 0.23 to 0.28, in the front end of the yolk. Spawning-time: V to VIII. 

 Southern North Sea, Channel, Atlantic. 



Caranx trachurus L. 

 ßß. Yolk divided by segmentation into numerous yolk-spherules. Anus 

 far back. Eggs very large. 



I. Egg containing 1 — 6 clear-yellow oil-globules, one large globule 

 lying in the front part of the elongated and spindle-shaped 

 yolk-sac. 



Diameter of egg: 2.4 — 2.75. Spawning-time: VIII. 



Atlantic Ocean. ? Conger niger Cuv. 



II. Egg containing colourless, round oil-globule of O.37 to 0.47 mm. 



Diameter of egg: 1.70 to 1.85. Spawning-time: IV. 



Norwegian Channel, Atlantic. * Argentina sphyraena L. 



