The True Sharks 217 
Manta birostris. It is said to be much dreaded by the pearl- 
fishers, who fear that it will devour them “after enveloping 
them in its vast wings.’’ It is not likely, however, that the 
manta devours anything larger than the pearl-oyster itself. 
Manta hamiltoni is a name given to a sea-devil of the Gulf of 
California. The European species Mobula edentula reaches a 
similarly enormous size, and Mobula hypostoma has been scantily 
described from Jamaica and Brazil. Mobula japonica occurs 
in Japan. A foetus in my possession from a huge specimen 
taken at Misaki is nearly a foot across. In Mobula (Cephaloptera) 
there are teeth in both jaws, in Manta (Ceratoptera) in the lower 
jaw only.* In Ceratobatis from Jamaica (C. robertst) there are 
teeth in the upper jaw only. Otherwise the species of the three 
genera are much alike, and from their huge size are little known 
and rarely seen in collections. Of Mobulide no extinct species 
are known. 
