307 _ 
slightly similar to the basketwork of the Cyclostomes (Fig. 4). It 
should here be noted to avoid confusion that W. N. PARKER, in his 
translation of WIEDERSHEIM, applies to this basketwork the term “extra- 
branchials”!), thus using it in an entirely different sense. The sting- 
Fig. 3. Fig, 4. 
Fig. 3. Second branchial arch of Raja radiata, showing the extrabranchial 
cartilage resulting from the fusion of the branchiostegal rays. (Dorsal view.) 
Fig. 4. Third branchial arch of Torpedo WEEE showing more complete 
fusion of the branchiostegal rays. (Dorsal view.) 
ray, Trygon pastinaca, has only four extrabranchials on either 
side, the one belonging to the hyoid arch being missing. In its place, 
I found on the dorsal side the first two branchiostegal rays of the 
hyoid arch fused with the basal end of the extrabranchial on the first 
branchial arch. Except in the case of this one cartilage there is no 
fusion of the branchiostegal rays in this species, although they slightly 
broaden out and curve over the top of the lamellae. Owing, perhaps, 
1) Elements of the Comparative Anatomy of Vertebrates. From the 
German of Rosert WIEDERSHEIM by W. Newton Parker, Macmillan & Co. 
1886, p. 63, 74. 
