. Carnegie Institution of Washington publication. THE EGG-CAPSULE. 31 CLASSIFICATION OF Fig. 14.—Egg-capsule of fossil Cliimaeioid, Ischyodus(Aletodus). from Dogger beds (Jurassic), Germany. After Jaekel. Actual From the materials provided in the present table and figures the egg-capsules of Chimseroids may be classified on some- what the following basis : Callorhynchus. (Fig. 15 a-f.) Capsules with case spindle-shaped; snout-sheath subequal in length to the tail-sheath; lateral web broad, exhibiting stout rugje; of these a conspicu- ous pair proceeds outward from hinge of opercular
. Carnegie Institution of Washington publication. THE EGG-CAPSULE. 31 CLASSIFICATION OF Fig. 14.—Egg-capsule of fossil Cliimaeioid, Ischyodus(Aletodus). from Dogger beds (Jurassic), Germany. After Jaekel. Actual From the materials provided in the present table and figures the egg-capsules of Chimseroids may be classified on some- what the following basis : Callorhynchus. (Fig. 15 a-f.) Capsules with case spindle-shaped; snout-sheath subequal in length to the tail-sheath; lateral web broad, exhibiting stout rugje; of these a conspicu- ous pair proceeds outward from hinge of opercular valve. No serrulse present, the opercular ridges merely separating to admit water, as in related structures in sharks. No caudal pores; in their place a slit on each side of tail-sheath opening on the ventral side in the angle between web and case. -Anterior lip of operculum transverse, situated on dorsal side at a considerable distance from anterior margin of capsule. No dorsal keel. Heavy cap- sules, leathery and glabrous. No capsules of Callorhynchus are known to be definitely associated with par- ticular species, although many of the speci- mens preserved in museums are ascribed to " C. ; From a study of the capsules of the species of Chimaera, * however, it is clear that the differences between the capsules described are such that we can not believe that they belonged to the same species. Thus the Chilean capsule (fig. 15), described by Jaekel as "Gr/. antarctiats" (a synonym of C. cal- lorhyncluts of Valenciennes) is probably of a different species from the similar egg- case (fig. 15a) figured by Dumeril, and this in turn is notably different from sev- eral specimens in the zoological museum of the Jardin des Plantes, which the writer was recently permitted to examine through the courtes}' of Professor Vaillant. The latter capsules are accordingly figured * Variation of the capsules within the range of the species was studied by the writ
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