GASTROPODA. 547 



covering the long arcuate gill. Genital pore near anterior end of 

 dorsal slit. Foot narrower than the body, long, acute behind. Radula 

 wide, with well-developed triangular central tooth with serrate cusp ; 

 the laterals narrower, with the cusp long and serrate on both edges ; 

 marginals with the basal plates shorter, cusps longer. Jaws wide, 

 composed of many minute chitinous elements. 



Shell very minute and orbicular, or wanting. 



Distribution. Mediterranean, Red Sea. Indian Ocean, Antilles, 

 Australasia, &c. 



Sect. 1. ACLESIA, Rang, 1828. 

 Aclesia, Rang, Hist. Nat. Aplys., 68. Type : Bursatella Savigniana, Audouin. 



Body plump, long-oval, with| moderately stout short neck and 

 head, and short conic tail. Sole rather broad. Integument of the 

 whole upper surface bearing numerous digitate or branched append- 

 ages, with simple ones among them. Lateral labial processes broad 

 and well developed. 



Distribution. Tropical and southern temperate seas. 



1. Notarchus glaucus, Cheeseman, 1878. Plate 36, fig. 1 



Aclesia cjlauca, Chsm., P.Z.S., 1878, 277, pi. 15, f. 4 ; T.N.Z.I., xi. 1878 (1879), 

 379, pi. 16, f. 4 ; M.N.Z.M., 123. Notarchus glaucus, Chsm., Man. 

 Conch. (1), xvi, 146, pi. 43, f. 34 ; Heclley, P.L.S. N.S.W., 1900, 97, pi. 4. 



Body from 3 in. to 5 in. long, about ovate when at rest, but capable 

 of considerable extension, a little contracted behind the head, then 

 elevated, and suddenly sloping to a point posteriorly ; entirely covered 

 with numerous simple and branched tentacle-like processes, the largest 

 of which are sometimes 8 lines long. Colour of the sides pale greyish- 

 brown, passing on the back into a dull sea-green ; the whole surface 

 with numerous irregularly shaped black blotches that are longest on 

 the back. Along the back there is also a double row of from 8 to 12 

 emerald-green specks, each surrounded with a zone of umber. Dorsal 

 tentacles f in. long, folded down the outer side so as to appear tubular, 

 beset with filiform appendages. Labial tentacles similar in shape, but 

 rather larger. Branchial cavity large, protected by the folded-in edges 

 of the mantle, branchiae quite internal. Foot long and narrowed, 

 pointed behind, without side lobes as in Aplysia ; sole pale sea-green. 

 Mouth roundish, placed under the head. Odontophore with very 

 numerous rows of simple hooked teeth. Gizzard strengthened with 

 large triangular calcareous plates. Shell none. (Chsm.) 



Type (?). 



Hob. Auckland Harbour, rather sandy localities, near the extreme 

 verge of low- water mark (Cheeseman). Also Port Jackson (Hedley). 



Remark. This animal possesses the power of emitting a purple 

 fluid, but only in small quantity, and it may often be handled without 

 anything of the kind being observed. 



