IIELICTNID;E PnOLADIDiE. 
165 
(Stoliczka) and rawcaiana (Bens.) : Stoliczka & Theobald, J. A. S. B. xli. 
pt. 2, p. 332, pi. 11. figs. 5 G. 
Hydrocena milium (Ben.s.). God win- Austen suggests it may be founded 
on iuimaturo specimens of Pupa plicidens : B. Z. S. 1872, p. 515, pi. 30. fig. 3. 
SOLENOCONCIIiE. 
Dcntalium agile, sp. r\.,—incertum (Philippi, Moll. Sicil., nee Desh.), allied 
to 7). ahysftovum (IM. Sars), remarkably active in its movements, from the 
Ijofoden Islands, in 200- 300 fathoms : Sars, llemark. Forms &c. pp. 31-34, 
pi. 3. figs. 4-16. 
Pentaliiim grncile (.TcfTr., \?>10)—Jllum (Sow., 1800), Bay of Biscay and 
Mediterranean : P. Fischer, .1. do Conch, xx. pp. 140-142, pi. 5. fig. 5. 
Cadulus minutus, sp. n., II. Adams, P. Z. S. 1872, p. 10, pi. 3. fig. 9, Bed Sea. 
LAMELLIBRANCniA. 
INCLUSA. 
Pholadida?. 
The luminous organs of Pholas are formed by ciliated epithe- 
lium, containing in its cells the special granular substance which 
renders the water luminous, and mixes with the mucus wdiich 
comes from the surface of the animal. They are found under 
the superior edge of the mantle, and in triangular spots and 
cords of white colour, standing out in relief on the mantle and 
siphon. The excretion of this substance can be caused by stimu- 
lants; and it becomes luminous by agitation, contact with fresh 
water, electricity, or heat ; the light can be excited and main- 
tained by air and oxygen, even during the putrefaction of the 
animal, for a long time. This light is monochromatic, like that 
of Beroe, Pelagia, &c. P. Panceri, Q. J. Micr. Soc. (2) xii. 
pp. 254<-260, with a woodcut. 
On the boring-instruments of Pholas Candida, cf. Robertson, Rep. Brit. 
Assoc. 1872. 
P. crisjiota and Candida (L.) once found at Kiel in rotten wood : Meyer & 
Mobius, Fauna der Kieler Bucht, ii. pp. 127-133, pi. 21. figs. 1-7 and 8-11. 
P. pacijica, sp. n., Stearns, Conch. Mem. vii. (1871), Alameda, San Fran- 
cisco Bay, California. 
Xylophaga dorsalis (Turt.). Some particulars concerning its boring, by 
Brogger, Bidrag Kristianiafj. moll. Faun. pp. 36-37. Pieces of wood con- 
taining this bivalve show outside only many very small holes, 2 millims. 
broad, clustered together; these holes are continued inwards into hollow 
radiating tubes, which at first run transversely, then more obliquely, and 
finally parallel to the fibres of the wood. 
Verkriizen repeats his observations concerning this animal (see Zool. Rec. 
viii. p. 166) in his journal 'Norwegen, seine Fjorde und Naturwundcr,’ 
pp. 36-43, adding figures (pi. 1). 
