49 



Shell internal, situated at the hinder extremity above the branchia, 

 white, calcareous, uncoiled, consisting of one or two volutions, thick- 

 ened at the free " sutural line," convex externally and concave within 

 cup-shaped at the commencement, with the outer edge extended by a 

 broadish membranous expansion. Total length 33 millim. ; cephalic 

 disk 18 long and 16 wide at the broadest part; shell with a greatest 

 diameter of 8 millim. ; and about 2 in height. (Smith'). 



Thursday Island, Torres Straits, 4-5 fathoms, on a sandy bottom. 

 (Coppinger). 



Doridium marmoratum SMITH, Zool. Coll. 'Alert,' p. 87, pi. vi, 

 f. I-I 4 (1884). 'Not Doridium marmoratum Cantraine, 1835. 



The only species which appears to have been recorded from the 

 Australian coasts is Aglaia lineolata, figured by H. & A. Adams in 

 the Genera of Recent Mollusca, vol. iii, pi. 58, fig. 4. This differs, 

 however, in the form of the anterior dorsal disk and its small size 

 in proportion to the hind part of the animal in addition to which 

 the color and markings appear to be quite distinct. Aglaia giglio- 

 Hi, from Japan, described by Tapparone-Canefri (Voy. Magenta, p. 

 110, pi. 1, fig. 18), may be distinguished by the posterior lobation of 

 the cephalic disk, different color, and apparent different position of 

 the branchial plume. 



Doridium cyane,um, D. nigrum, and D. guttatum, described by 

 Dr. Von Martens from the Indian Ocean, have not yet been figured. 

 Until all these exotic species have either been compared or much 

 more amply described and illustrated, there will remain much un- 

 certainty respecting the identification of all or any one of them. 



A. LINEOLATA H. & A. Adams. PI. 1, fig. 7. 



No description of this species has been published, to my knowl- 

 edge. As figured by A. Adams, the shields and outside of parapodia 

 are transversely lineolate with purplish on a light brown ground ; 

 insides of parapodia very dark ; posterior wings of mantle short, 

 without a filament. Shell unknown. 



Australia (Gould). 



Aglaia lineolata H. & A. Ad., Gen. Rec. Moll, ii, p. 27, iii, pi. 58, 

 f. 4. 



A. CYLINDRICA Cheeseman. Unfigured. 



Body elongated, almost cylindrical, 1-1 i in. long; color a deep 

 rich velvety-black. Cephalic disk narrow, oblong, quadrate, slightly 

 4 



