306 
Fig. 1. Fig. 2. 
Fig. 1. Visceral skeleton of Raja erinacea. (Ventral view.) pt.qv pterygo- 
quadrate. mck Meckew’s cartilage. hm hyomandibular. hy hyoid. dr! to br° first to 
fifth branchial arches. va! to va first to fifth ventral extrabranchial cartilages. The 
labial cartilages are omitted. 
Fig. 2. Dorsal view of Fig. 1. dx! to da® first to fifth dorsal extrabranchial 
cartilages. 
extremities of one or two of the branchiostegal rays, an occurrence 
also variable and likely to be found on either side. In Raja 
radiata, however, they seem be formed entirely by the expansion 
and fusion of these extremities (Fig. 3). In Torpedo ocellata 
the same fusion is found, together with a curious irregularity of out- 
line on both sides of the cartilages that gives them an appearance 
