150 54 
East of Koh Chuen, 9—10 fathoms, shells (2). 
Long. 30 mm. 
Distribution: — Aden (Epc. Smiru), Durban (SowEerBy). — Moreton Bay, 
Queensland (REEVE). 
Note. In Pl. I, Figs. 19—20, I have given figures of a young specimen of Pinna 
sp. (taken between Koh Kut and Koh Kahdat, in 10 fathoms; 18 mm. long) with 
a very well-preserved prodissoconch, which is distinctly separated from, and highly 
different from the later increment to the valve. (R.T. JAckson says in “Phylogeny 
of the Pelecypoda,”’ Boston 1890, p. 3382, when mentioning the group Perna, Avicula, 
and their near allies: “The genera Malleus and Pinna might be considered in this 
section, but I have not succeeded in getting very young specimens of either genus,” 
and later on, p.385, “I have not had opportunity to study the Pinnide satisfactorily 
as attempts to obtain very young specimens have so far failed;’ in the specimen 
of a young Pinna sp. figured in his Fig. 53 the prodissoconch is also wanting). 
PELSENEER,' in his “System,” places the genus Pinna under the order Eulamelli- 
branchia, near to Ostrea and Lima, while Avicula (Pteria) is found under the 
order Filibranchia. F. BERNARD,” who has later examined the development of the 
shell of the gen. Pinna, has reached another opinion, though the material at his 
disposal, as he says, has been very small. The result of his researches is, that the 
gen. Pinna belongs to Mytilidae. The scanty material at my disposal prevents me 
from entering more fully into the question. 
Fam. Spondylidae. 
Spondylus Sinensis, Sow. 
Spondylus Sinensis, Sowersy, Thesaurus Conchyliorum, I, 1847, p. 427, pl. 87, figs. 32—34. 
= — = Reeve, Conchol. icon., IX, 1856, Spondylus, Sp. 7. 
S. of Koh Chuen, 30 fathoms, shells (1). West coast of Koh Chang, 10 fathoms, 
mud (1 + 2/2). Between Koh Chuen and Koh Chang, 15 fathoms, mud ('/2). E. of 
Koh Mak, 20 fathoms, mud (1). Between Koh Kut and Koh Kahdat, 10 fathoms, 
shells (1 + ‘/2). S. of Koh Kahdat, 8—10 fathoms, mud (1). W. of Koh Kut, 15 
fathoms, mud (2). 
Long. 3 mm., alt. 3°55 mm. 
— 46 mm., — 56 mm. 
Distribution: — Poulo Condor, Cochin China, Annam, China, Japan. 
The valves are quite white in one of the specimens from the Gulf of Siam.” 
Spondylus coccineus, Lam. (Reeve). 
Spondylus coccineus, Lamarck, Hist. nat. d. anim. s. vert., VI, 1 part., 1819, p. 190, No. 11. — éd. 2, VII, 1836, 
p- 188, No. 11. 
= = = Reeve, Conchol. icon., IX, Spondylus, 1856, Sp. 44. 
— ocellatus, REEvE, Conchol. icon., IX., Spondylus, Sp. 43. 
1 A Treatise on Zoology, ed. by E. Ray Lanxester, V, Mollusca by P. PELSENEER, London 1906, p. 263. 
2 Recherches ontogén. et morphol. sur la coquille d. Lamellibranches. Annales d. sc. natur. Zoologie, 
VIII, Paris 1898, pp. 45 et 85—86. 
8’ Comp. Dunker, Index moll. mar. Japon., 1882, p. 245. 
