PLATE XL. 



Fig. 1. — Megalatractus aruanus, Linn. Operculum. 



Fig. 2. — M. maxinms, Tryon. Nervous sy.stem, as seen in situ. 



Fig. 3. — 31. maxiinus, Tryon. Nervous system; the cerebral 

 loop cut through and laid back, so as to show the 

 ganglia below. 



Fig. 4. — M. maximus, Tryon. Dentition. 



Fig. 5. — M. maximus, Tryon. Dorsal view of body showing penis, 

 and vas-deferens. 



For explanation of letters, see p. 450. 



