PLATE 61. 



PLATOSOMIA and ANTACEA. 



Fig. 1-3. Nabcacion MARMORATUS (Page 305). Fig. 4-5. Naecacion nobilianus (Page 310). 

 Fig. 6. Narcine timlei (Page 300). Fig. 7-8. Chlamydoselachus anquineds (Page 14). Fig. 

 9-11. Rhina caufornica (Page 253). 



1-3. Various stages from De Sanctis, 1872. 



4-5. Four fifths and natural length. M. C. Z. 1016. 



6. One and two thirds natural length. 



7-8. One and three fourths natural length. M. C. Z. 1285. 



9-10. Five sixths natural length. M. C. Z. 916. 



11. Two and two thirds natural length. M. C. Z. 916. 



The first three figures illustrate the squaliforra raiiform and torpetliform stages socalled by De 

 Sanctis (1872, AUi Reale accad., 5, pi. 1, fig. 3, G, 9.) In fig. 3 the forward extension of the pectorals, at 

 the sides of the batteries, is strongly marked while the lateral growth of the antorbital process ultimately 

 forming the front of the disk has hardly begun; at this stage the latter merely forms a pad in front of the 

 head. Figures 4 and 5 from a specimen off the coast of New England illustrate the lateral growth of the 

 antorbital portions of the disk to meet the forward extensions of the pectorals and, with the obliteration 

 of the notch opposite each eye, complete the disk. See the .skeleton of N. marmoralus on Plate 67, 

 ao. The batteries are well developed and the disk completely outlined at a very small stage of Narcine 

 timlei, fig. 6. In connection with fig. 7-8, showing the young Chlamydoselachus with well differentiated 

 fins and extern.al gills, see also fig. 4-5, Plate 59. The embryo of Rhina mliforiiica, fig. 9, was attached 

 to an enormous mass of yolk, longer and many times the weight of the little shark. Figures 10 and 11 

 show the intestines and their connection with this yolk, the dotted lines indicating the entrance in front 

 of the spiral folds. 



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