162 Transactions. — Zoology. 



Art, XXI. — Notes on some Brancliiate MoUusca. 

 By Professor F. W. Hutton. 

 [Read before the Philosophical Institute of Canterlury, 7th July, 1881.] 

 Plates VI and VII. 

 Octopus Maorum. Dentition. The central tooth varies much in shape ; 

 usually it has only a median cusp, ■which carries a long cutting point at its 

 end, and a small one on each side, but sometimes there is a small cusp behind 

 each smaller cutting point. The first lateral is rudimentary, with a small 

 curved cusp. The second lateral is short and broad, its breadth being four 

 or five times its length, and is more or less curved ; it has a short triangu- 

 lar cutting point at each end, the outer one of which is hidden by the base 

 of the third lateral. The third lateral has a quadrate base, and a long 

 curved cutting point, blunt at the end. . The marginal plate is large, its 

 breadth more than twice its length ; it tapers outwards ; the anterior margin 

 is slightly concave, the posterior is convex. (PI. VI., fig. a.) 



The di'awing is taken from a very small specimen obtained at Welling- 

 ton. 



Ommastrephes sloanii. Dentition. The central tooth is tricuspid, the 

 median cusp rounded, the side cusps sharply pointed ; the median cusp 

 carries a long narrow cutting point. The first lateral is bicuspid ; the outer 

 cusp is sharp and without a cutting point, the inner cusp is rounded, and 

 with a narrow sharp cutting point slanting slightly inward. The second 

 lateral has a quadrate base, and a single cusp bearing a long sharp curved 

 cutting point. The third lateral is like the second, but has an aculeate 

 base. The marginal plate is small and oval. (PI. VI., fig. b.) 



The drawing is from a very small specimen obtained at Dunedin. 

 EuTHRiA LiNEATA. Dentition. The central tooth is nearly twice as broad 

 as long, with three sharp denticles on the upper anterior surface. The 

 laterals have a long curved denticle on the outside and two small ones close 

 together on the inside. They lie close to the central tooth. (PI. VI., fig. d.). 

 The nucleus of the operculum is apical, forming the apex. The di'awing 

 was made from a specimen an inch in length, intermediate between varieties 

 A. and C. It was obtained at Sumner. 



CoMiNELLA FUNEREA. Animal yellowish white. The eyes are half 

 way up the tentacles, which are marked with black in the region of the eyes. 

 Top and sides of the head with dead- white spots. Siphon long and recurved, 

 white speckled with black. Foot slightly expanded and emarginate in 

 front, rounded behind ; with two black spots in front. 



Operculum with the nucleus apical, within the apex, the margins simple. 



