BY C. HEDLEY. 127 



From Polynesia the researches of Garrett and Pease have brought 

 to light P. grandis, ovalis, delicatulits and tessellatus, Pease (Am. 

 Journ. Conch, iv. pp. 78-80, pis. ix. and x.). The species under 

 consideration resembled none of these, but of all the figures and 

 descri|)tious within my reach it most approximated to those of P. 

 testudhiarius on p. 571 of Fischer's Manuel de Conchyliologie. 



Most opportunely, whilst still investigating the new species, I 

 received from Prof. Yayssi^re of Marseilles, France, a welcome 

 gift of a copy of his " Recherches Zoologiques et Anatomiques sur 

 les Mollusques Opistobranches du Golfe de Marseille," " Pt. i. — 

 Tectibranches," forming Tome ii. — Zooiogie — of the " Annales 

 du Musee d'histoire naturelle de Marseille." The full account, 

 the best hitherto given, herein contained, of the above mentioned 

 mollusc, confiraied me in recognising in the Mediterranean animal 

 the nearest known relative to our Sydney slug. 



For the French species, Prof. Vayssiere adopts the name of 

 Oscanius tuberciUatus, Delle Chiaje ; embracing as synonyms 

 Pleurohranchus forskahli, Delle Chiaje, P. mammillatus, Sclinltz, 

 and P. testudinarius, Cantraine. 



My correspondent amends and expands the genus Oscanius of 

 Leich on p. 121 of the above quoted woi'k. According full 

 generic rank to this division, he unites with it as an absolute 

 synonym, Gray's genus Susania (Guide to the Mollusca of the 

 British Museum, 1857, p. 202). This is the interpretation of 

 Oscanius here followed. 



Oscanius hilli, n.sp. 



Animal elliptical, thick, subglobose ; in life, as well as I can 

 recollect, dark plum colour ; as contracted in alcohol measuring 

 140 mm. in length by 120 mm. in width and 50 in height; without 

 a shell. Mantle very large, thick and muscular, overlapping the 

 body so as almost to envelope it ; irregularly covered outside by 

 numerous large, warty protuberances ; deeply, squarely notched in 

 fro.it, entire throughout the rest of its circumference. Rhino- 

 phores appressed to each other, externally split to the base, thick 

 and subcylindrical. Eye not observed. Foot large, somewhat 



