204 PROCEEDINGS OF THE MALACOLOGICAL SOCIETT. 



Chione mesodesma. (Quoy & Gaimard). 

 Venus mesodesma, Q. & G. : Voy. Astrolabe, Zool., vol. iii (1834), 



p. 532, pi. Ixxxiv, figs. 17-18. 

 Venus spiirca, Sowerby : Proc. Zool. Soc, 1835, p. 23; Thesaurus 



Conch., vol. ii, tigs. 92-97 ; Eeeve, Conch. Icon., figs. 90a-b. 

 Venus i<pissa, Deshayes : in Lamarck's Anim. s. Vert., 2nd ed., vol. vi 



(1840), p. 373. 

 Venus mesodesma, Gray: in Dieffenbach's Travels in N. Zeal., vol. ii 



(1843), p. 251. 

 Murcia scansilis, Eomer : Mai. Blatter, vol. vii (1860), p. 161. 

 Chione mesode,sma, Hutton : Cat. Mar. Moll. N. Zeal., 1873, p. 70; 



Journ. de Conch., vol. xxvi (1878), p. 49 ; Man. N, Zeal. Moll., 



1880, p. 148. 

 Venus mesodesma, Hutton: Proc. Linn. Soc. N.S. Wales (1), vol. ix, 



p. 523. 

 Venus crassa, Suter : Trans. N. Zeal. Inst., vol. xxxiv (1902), p. 221 



(not Q. & G.). 

 Chione crassa, Suter: Index Faunoe Nova? Zealandiae, 1904, p. 39 



(not Q. & G.). 

 The diagnosis is to be found in Hutton's Manual, etc. Quoy & 

 Gaimard remark : " A small species, a little resembling Ilesodesoia 

 striata in form, and the regular longitudinal striae. The shell is oval, 

 nearly equilateral, light yellowish, with some transverse triangular 

 flames of a pale reddish colour. The interior of the valves is bright 

 violet. The lunule, of the same colour, is elongated oval. The 

 beaks are white ; the margin of the valves denticulated on the inner 

 side. There is no anterior lateral tooth. Length 20'2o, height 15 75, 

 diam. 9 mm." 



This species is easily distinguished from C. crassa by its much less 

 gibbous form, the lanceolate lunule, and the less prominent concentric 

 ribs. In colour-markings this species is exceedingly variable, and it 

 is very often beautifully ornamented with zigzag lines. It is the 

 most abundant bivalve on tbe east coast of the North Island, and 

 especially on Tiri-Tiri Island in the Hauraki Gulf, where I have seen 

 tons of this species piled up on the bench. By dredging in depths 

 from five to thirty fathoms in Hauraki Gulf great quantities of valves 

 are always met with. 



Chione mesodesma (Q. & G.), subsp. violacea (Q,. & G.). 

 Venus violacea, Q. & G. : Voy. Astrolabe, Zool., vol. iii (1834), p. 533, 

 pi. Ixxxiv, figs. 19-20. 

 A small orbicular subspecies with cutting margins, denticulated 

 interiorly ; subequilateral, slightly gibbous near the apex, regularly 

 longitudinally grooved, lamellae flat, directed upwards. The beaks 

 are rounded, directed forwards, heart-shaped, also the lunule, which is 

 short, sharply defined. The escutcheon is elongated and well marked. 

 Colour reddish-violet with a few white spots and two rays of greenish 

 colour descending from the umbones. Interior white, broadly 

 bordered Avith violet. No anterior lateral tooth. Length 15'75, 

 height 12-25, diam. 6-75 mm. (Q. & G.). 



