552 GASTROPODA. [Opisthobranchia, 



longitudinally, quite long, and with 16 to 25 pinnules on each side ; 

 the posterior half of gill free. Genital orifices close together, surrounded 

 by a not prominent fold. Length, 20-30 mm. ; breadth, 10-15 mm. 



Jaws composed of pieces having 5 denticles on each side of the 

 terminal point. Radula with formula 70 + 0+70; the lateral teeth 

 with terminal hooklet but no denticles below it. 



Shell auriculate, the spire a little projecting ; solid, thick but 

 transparent, of a dull amber-yellow colour, slightly iridescent inside. 

 Nucleus very small, about 2 whorls ; the concentric growth-lines 

 very distinct. 



Diameter, 4-6-8 mm. ; height, 8-13 mm. 



Hob. Chatham Islands (Schauinsland) ; Hauraki Gulf, under 

 stones at low-water mark (H. S.). Mediterranean ; the type from 

 Nice ; Azores, in 130 fathoms ; eastern and western parts of the 

 Atlantic. 



Remarks. I found specimens spawning on the 24th July. 1906. 



Genus 2. PLEUROBRAXOH.EA. Leue, 1813. 



Pleurobranchcea, Leue, De Pleurobranchsea novo Moll. Genere, 1813, 1-13, 

 plate. Type : P. Meckelii, Blainville. Pleurobranchidium, Blainville. 

 Cyanogasler, Rudolphi. Pleurobranchcena, Meckel. 



Body oblong, the united mantle and veil smaller than the foot. 

 Serrate in front and produced at the lateral angles, its edge slightly 

 overhanging on the right side, but not on the left, posteriorly, or in 

 front. Rhinophores inserted far apart, apparently on the mantle. 

 Genital apertures close together. Mouth proboscidiform. Foot with 

 a more or less visible gland on the posterior part of the sole, and a 

 spur or horn on the tail. 



Jaws present, composed of elongated plates. Kadula without 

 central tooth, the laterals slender, with a single long accessory denticle 

 on the main cusp. 



Shell wanting. 



The species are few and widely scattered. 



KEY TO SPECIES. 



A. Colour dirty -white, with light-brown spots ; sole yellowish maculata. 



B. Colour light grey, with anastomosing greyish-brown lines 



and white dots ; sole grey . . . . . . . . novce-zealandice. 



1. Pleurobranchaea maculata, Quoy and Gaimard, 1832. Plate 23, 

 fig. 17. 



Pleurdbranchidium maculatum, Q. & G., Voy. Astrol., ii, 1832, 301, pi. 22, 

 f. 11-14. Pleurobranchcea maculata, Q. & G., Man. Conch. (1), xvi, 227. 

 pi. 53, f. 88, 89; Spengel, Zool. Jahrb. Suppl., Fauna Chilensis, 1898, 

 492-94, pi. 29, f. 2-9; Bergh, Reise Philipp., die Pleurobranchiden, 1898, 

 153, 154 ; Vayssiere, Ann. Sci. Nat., Zool., xii, 49-56, pi. 5, f. 238-50. 



Body thick, a little swollen above, covered with low wrinkles. 

 Colour dirty-white, with light-brown spots ; sole yellowish. Foot, wide, 



