CARD IT A. 



Plate II. 



Species 7. (Fig. a and d, Mus. Cuming ; Fig. b, cand e, 

 Mus. Stainforth.) 



Cardita crassicostata. Card, tesht elongatd, antici 

 brevissimd, coarctatd, albicante, incarnato-tinctd, ae- 

 ruleo- aut rubido-fusco pallid'e nebulosd, lineis spa- 

 diceis undatis ornatd ; costatd, costis undecim, tribus 

 majoribus, crassis, imbricato-squamosis. squatnis flex- 

 uosis obtusis, nunc erectis, nunc incumbentibus, squamis 

 superioribus erectioribus. 



The thick-ribbed Cardita. Shell elongated, very 

 short and contracted anteriorly, whitish stained 

 with flesh-colour and clouded either with blue or 

 reddish-brown, and further ornamented with fine 

 brown zigzag lines ; ribbed, ribs eleven in number, 

 three of much larger dimensions than the remainder, 

 thick, imbricately scaled ; scales fiexuous, obtuse, 

 sometimes erect, sometimes bending over each other, 

 the superior scales always the most erect. 



Lamarck, Anim. sans vert., vol. vi. (Deshayes' edit.) 

 p. 430. 



Testa fossilis. Cardita crassa, Lamarck. 



Testa juvenis (Fig. 7 a.) subdepressa, squamis regvlaribus. 

 Shell in young state, rather depressed ; scales regular. 



Testa senior (Fig. 7 b and d.) gibbosa, plus minusve ar- 

 cuatim contractu ; squamis crassis, irregularibus. 



Shell in a more advanced state, gibbous, more or less 

 arcuately contracted ; scales thick and irregular. 



Hab. Putao, Island of Luzon, Philippines (found in 

 coarse sand at the depth of six fathoms) ; Cuming. 



Variety (1. (Fig. 7 c.) 



Testa rosea, lineis undatis indistinctis. 

 Shell rose-colour, zigzag lines indistinct. 



Variety y. (Fig. 7 e ) 



Testa crocea, lineis undatis quoque indistinctis, costarum 



interstitiis subolivaceo-fuscis. 

 Shell rich saffron-yellow, zigzag lines indistinct also, 



interstices between the ribs faintly stained with 



olive-brown. 



Variety c. (PI. 3. Fig. If, Mus. Cuming.) 

 Testa costis squamisque albis, costarum interstitiis oliva- 

 ceo-fuscis. 



Shell with ribs and scales white, interstices between the 



ribs olive-brown. 



Cardita Tridacnoides, Menke. 

 Hab. New Holland. 



This beautiful species of Cardita varies so exceedingly 

 in growth and distribution of colour, that it requires a 

 large series of specimens to establish the complete spe- 

 cific connection of the varieties above noted. 



Variety a. The normal variety is exceedingly well 

 characterized by the small zigzag lines which cross the 

 interstices between the ribs and the spacious diamond- 

 shape lunule between the superior rib of each valve 

 when the shell is closed, as shown at Fig. 7 b. 



Variety (3. The entire shell is of a deep rose-colour ; 

 the zigzag lines become indistinct, and the interstices 

 between the ribs exhibit some indication of a faint 

 longitudinal streak of olivaceous-brown. 



Variety y. The rose-colour which distinguishes the 

 preceding variety is exchanged in this for a bright 

 saffron -yellow. A few zigzag lines are scattered here 

 and there upon the shell, the olivaceous intercostal 

 streak becomes more conspicuous, and the scales larger 

 and more like those of a small Tridacna. 



Variety <5. I am not surprised to find that this beau- 

 tiful miniature Tridacna-like variety has been described 

 as a new species ; M. Menke lacked the beautiful series 

 of specimens it has been my fortune to examine to 

 discover its identity. There is no indication of colour 

 in any part of this shell, except in the olivaceous lon- 

 gitudinal streak between the ribs, which is here dark, 

 and especially prominent by the contrast. The scales 

 are large and very symmetrically furbelowed. 



The specimens which have furnished me with the 

 above remarks are in the collections of Messrs. Cuming. 

 Stainforth, Metcalfe, Deshayes, Petit, Delessert ; the 

 British Museum, and the Museum, Jardin des Plantes. 



Species 8. (Fig. a and b, Mus. Cuming.) 



Cardita pica. Card, testd elongato-ovatd, gibbd, alba, 

 nigro aut fusco varie inquinatd ; costis septemdecim 

 sedecimve, in medio angulatis, subtiliter squamosis; 

 intus alba, post in nigerrimo-fuscd. 



The pied Cardita. Shell elongately ovate, gibbous, 

 white, variously daubed or blotched with black or 



June IS 13. 



