Atagema :\ GASTROPODA. 571 



1. Atagema carinata, Quoy and Gaimard. 1832. Plate 23, 

 figs. 18, 18a. 



Doris carinata, Q. & G., Voy. Astrol., ii, 1832, 254, pi. 16, f. 10-14 ; Dieff. 

 N.Z., 244; C.M.M., 53'; Abraham, P.Z.S., 1877, 211; Chenu, Man. 

 Conch., i, 405, f. 3052 ; M.N.Z.M., 128. Atagema carinata, Q. & G., 

 Ad. G.R.M., ii, 60, pi. 64, f. 1 ; Crit. List, 38 ; Bergh, in Semper's Reise 

 Philipp., Malac. Unters., vi, 39, pi. 3, f. 8-11 ; Benham, T.N.Z.I., xxxvii, 

 319, pi. 18 ; Eliot, P. Mai. S., vii, 328. 



Body oval, with a somewhat arched back, which is finely shagreened ; 

 consistency leathery. Colour of the living animal pure-white, turning 

 to yellowish- white in alcohol. Mantle-edge broad and the foot pro- 

 jecting all round. The back carries a great median keel, which com- 

 mences anteriorly between the rhinophores. It is at first somewhat 

 low and narrow, then becomes thicker, and behind the middle of its 

 extent becomes elevated into a blunt point ; thence it continues as 

 a much narrower ridge to the gills. The projecting rhinophore-sheath 

 has a circular aperture. The club of the retracted rhinophore is closely 

 foliated, and terminates in a small papilla. The branchial cone con- 

 sists of 4 to 5 converging lappets with rounded ends. The deeply sunk 

 gill is formed of 5 or 6 tripinnate members, of which the two anterior 

 are the larger. The relatively thin anal papilla is curved forward, and 

 subcentral in position. The retracted tentacle is short, finger-shaped, 

 with a groove on the under-side. The foot stout and broad, rounded in 

 front, with a marginal furrow ; tail relatively short. 



Length, 25 mm. ; breadth, 14 mm. : height, 9 mm. (figure of type). 

 Length, 8-9 cm. ; breadth, 6-7 cm. ; height. 3-3 cm. (specimens from 

 Dusky Sound). 



Tt/jic in the Mus. Hist. Nat., Paris. 



Hah. Firth of Thames, type (Quoy and Gaimard) ; Dusky Sound 

 (E. Henry). 



Genus 6. CHROMODORIS, Alder and Hancock, 1855. 



Chromodoris, A. & H., Trans. Zool. Soc., v, 1855, 123 ; Monogr. Brit. Nudibr. 

 Moll., pt. 7, 1855, p. xvii. Type : Doris magnified, Q. & G. Glossodoris, 

 Actinodoris, Pterodoris, Ehrenberg, 1831. Goniobranchus, Pease, 1866. 

 Thorunna, Bergh, 1878. 



Form generally high, narrow, and limaciform. the mantle being 

 somewhat small at the sides, but expanding into a fairly ample frontal 

 and caudal veil. The coloration is brilliant. The foot usually projects 

 behind the mantle. The branchiae are simply pinnate, but are some- 

 times bifid, and vary considerably in their arrangement. The tentacles 

 are retractile. The labial disc has a strong armature of minute hooks. 

 The rhachis of the radula is either naked or bears thickenings, very 

 rarely true teeth. The laterals are numerous and hamate : the first 

 is denticulate on both sides, those which succeed it on the external 

 sides only, the outermost at the extremity only. 



The genus is chiefly found in warm seas, and is most abundant in 

 the tropics ; it is specially characteristic of the tropical Indo-Pacific. 



