BY WILLIAM H. HASWELL, M.A., B.SC. 439 



anterior extremity of the corpus callosum ; the posterior cornua 

 are rudimentary. The hippocampus major is well-defined and ends 

 in a prominent pes ; the hippocampus minor is comparatively low 

 and inconspicuous. 



Explanation of Plate xxi. 

 Fig. 1. — Upper view of the brain. 

 ,, 2. — Lower view of one half of the brain. 

 ,, 3. — Mesial lono-itudinarsection. 



On a New Genus of Fishes from Port Jackson. 

 By William Macleay, F.L.S. Plate xxii. 

 The Fish here described was captured in a seine net at Watson's 

 Bay by a fisherman, last Friday morning, was taken by Mr. 

 Mulhall, Sub-Inspector of Fisheries, to Dr. Cox, and was by him 

 presented to the Australian Museum. Finding it to be something 

 perfectly new, I lost no time in transferring to paper as accurate a 

 description of it as was possible under the circumstances, for 

 unfortunately the taxidermist of the Institution had already 

 skinned the fish, and thrown away the body. I have had there- 

 fore no means of ascertaining the size or shape of the air-bladder, 

 or the number of pyloric appendages, and my measurement of the 

 height of the body of the Fish as compared with its length, has 

 been also to some degree a matter of guess work. For the genus 

 I propose the name of Psilocranium from its bald head, and for the 

 species that of the learned President of the Commissioners of 

 Fisheries. 



Genus Psilocranium. 



Of elongate form, scarcely if at all laterally compressed. One 

 dorsal fin, the soft portion much larger than the anal fin. Caudal 

 fin forked. The lower rays of the pectoral fins simple. Teeth in a 

 viliform band in both jaws. Prseorbital and praeoperculum entire. 

 Scales large, thin, cycloid. Head naked, except on the operculum 

 which is clothed with small non-imbricate scales embedded in the 

 skin. Branchiostegals five, the inner one very small. 



