PLATE 69. 



Fig. 1-2. Sqdalus acanthias. M. C. Z. 35 (Page 192). Fig. 3. Ginglymostoma cirratum. 

 M. C. Z. 819 (Page 54). Fig. 4-6. Chlamydo.selachus anguineto. M. C. Z. 1247, 1285 (Page 14). 

 Fig. 7-8. MoBULA HYPosTOMA. M. C. Z. 683 (Page 453). Fig. 9-10. Rhinoptera jussibdi. 

 M. C. Z. 863 (Page 447). 



Figure 1, | natural .size, and fig. 2, natural .size, exliibit the outer and the internal yolk-sac, the 

 heart with arteries, the liver, the stomach, and the intestine. Figure 3, /j natural length, is the egg of 

 Ginglymostoma, the embryo showing through the shell. Figure 4-5, f nat., show the egg with the 

 embryo of Chlamydoselachus. Fig. 7-8 show the ajjpearance of the gill plates of Mobuhi, and fig. 

 9-10 those of Rhinoptera. There is in the latter a longitudinal division of the plates into upper and 

 lower parts, in fig. 9 there are also seen modifications to some e.xtent intermediate in character between 

 the plates in fig. 10 and those of Mobula. 



Figure 6, of Chlamydoselachus, was made for comparison with the type and with figures in more 

 recent articles by Furbringer and Goodey. In a number of points it is at variance with the figures men- 

 tioned and agrees more nearly with the type. There is no point behind the middle of the first basihyal, 

 as in Fiirbringer, 1903, Morph. jahrb. 31, pi. 27, f. 18 or in Goodey, 1910, Proc. Zool. .soc. Lond., pi. 43, 

 f. 6 "bbr. 1 (?)." The basibranchials are more numerous and regular than in either of the mentioned 

 figures. The hypobranchials are present in five pairs, the hindmost pair being displaced and resting 

 below the junction of the sixth ceratobranchial and the basibranchial; these cartilages are those figured 

 as the vestigial seventh arch, Goodey, loc. cU., pi. 43, fig. 6, "b a 7 (?)." The seventh arch was dis- 

 covered and figured by Furbringer, 1903, as an "eventuel Rudiment einer siebenten Kiemenbogens"; 

 it is of much greater development in this Plate than in either of the other figures. 



