Nr. 9] 



CONTHIB. TO THE LIFK HISTOHY OF THK FISHES 



•25 



emerge from between tbe long lu})es, which evidently indicate 



the fore-end of the egg, the shorter tubes being attached to the 



posterior part. It would moreover, be reasonable lo suppose 



that the young should emerge head foremost, and not tail first, 



and we might thus expect to fine Ihe point of snout lying to- 



wards the fore-end thus determined. This was also lound to be 



the case, albeit the longitudinal axis 



of the young fish does not coincide 



with the median line of the capsule, 



bul råtner with its diagonal, the 



point of snout being directed towards 



the one of the longer tubes. This 



gives us, then, the orientation of the 



eapsules, the long tubes indicaling 



the fore end, the flat broad side 



being the dorsal, and the co.nvex 



the ventral. The tubes of the fore 



end, which are easely pliable, and 



terminate in a thin thread, curve in 



over the lateral plane. The tubes of 



the posterior end are sliffer and Ihe 



points curve out from the lateral 



plane in towards the dorsal side. 



They are thus more hook shaped. 



The fore end of the capsule is as a 



rule cut off transversely, the posterior 



edge curving inward. The hooks at 



the hinder end are presumably de- 



signed to act as anchors, holding 



the egg fast to the bottom and pre- 



venting its being carried away by 



the currenl and washed ashore. It 



is then worlhy of note thai Ihe 



hooks in question ahvays curve over 



towards the dorsal side, whence it 



would seem Ihat the egg is inlended 



to lie on its back. On opening 



Ihe capsule, the inner side of the 



walls is found to be extremely 



smooth and and highly polishéd, 



lia ving an almosl metallic gleam. 



The thickness of the wall is V2 — 1 



mm. Both posterior and anlerior 



tubes communicate with the in 



terior cavity. In old eapsules, the 



Fig. ti. Egg capsule of Raja 



radiala from Gulosen 1 h> 1910 



abt. 80 m. (capsule nr. 5) 1. 54 



mm., b. -18 mm., thickness 15 



mm. Lateral keels slightly 



broader than usual and some- 



what expanded mediallv, giv 



ing the capsule itself the 



appearance of a longitudinal 



section of a barrel. Ven 



tral side of the ca 



sule removed. 



