446 Holt — On the Eggs and Larvce of Teleosteans. 



occurs in both Gobius and Callionjmus, though too much stress should not be laid 

 on a feature which appears in widely separated groups, and is variable within the 

 limits of a single genus.* 



In Callionymus and Gobius, the notochord cells (vacuoles) are smaller and less 

 inflated than those of the herring, which Kupffer (Entwickelung des Herings im 

 Ei. Jahresb. Comm. deutschen Meere. 1874-76: Berlin, 1878) has shown to arise 

 from more numerous and smaller roundish polygonal cells. Of the origin of those 

 in the dragonet and goby we have at present no knowledge. 



Cepolid^. 



Cepola rubescens (Linn.). The Red Riband Fish. 



(PI. XLViii., fig. 22.) 



A female of this species, 11-i- inches long, occurred in the stomach of a large 

 grey skate in Inver Bay, on tlie 25th of June. It was somewhat macerated, and 

 the ripe ovaries, with other viscera, were exposed. A number of ripe ova were 

 scattered about in the skate's stomach. The ovum (fig. 22) is translucent, with a 

 thin minutely-jjitted zona. The diameter is '72 mm. The yolk (?/.) is homogeneous, 

 translucent, and colourless, except at tlie periphery, which exhibits a brownish 

 opacity in optical section. It is somewhat collapsed, a condition which, with the 

 brownish tinge, is doubtless due to the action of the gastric juices. The zona 

 shows no sign of collapse, and appears perfectly spherical. There is a single large 

 oil-globule, l'35mm. in diameter, with a somewhat smoky mai'gin, like that of 

 Trigla gurnardus. 



From its small size, thinness of zona, and character of yolk, I am inclined to 

 regard this as a pelagic egg. My specimens were, of course, of no service in 

 demonstrating the buoyancy (or otherwise) of the living egg. 



This species is abundant in the Mediterranean, but the ova, if pelagic, have 

 escaped Raffaele's attention. 



* A unicolumnar notochord occurs 'm Pleicronectes americaniis. See Agassiz and Whitman, " The Pelagic 

 Stages of Young Fishes " — Memoirs of the Museum of Comparative Zoology, vol. xiv., No. 1, pt. i., pi. xvi., 

 fig. 5. It is not known to occur elsewhere in the Pleuronectidse. In the genus Clupea it is present in 

 C. harcngus, C. sprattus, and C. pilchardus ; but the notochord of C. sapidissima is multicolumnar. See 

 Ryder, " The Development of Osseous Fishes " — U. S. Commission of Fish and Fisheries, pt. .xiii., 

 Report of Commissioner for 1885, p. 523. 



