128 Proceedings of Boyal Society of Edinhurgh. [sess. 
The blood of Solen contains haemoglobin; and this pigment is 
present in special corpuscles."^ 
MacMunn f has proved that the brown colour of Solecurtus stri- 
gillatus (belonging to the family Solenidae) is due to the presence 
of hasmatoporphyrin, and it is very probable that the blood of this 
Mollusc also contains haemoglobin. 
The author J has already given some details concerning the blood 
of certain representatives of the higher MoUusca and Crustacea, 
and consequently the following data may be considered as addi- 
tional matter to that already published. 
The orange-coloured blood or haemolymph of Chito7i (one of the 
Polijplacopliora) and Patella % (one of the Brancliiogasteropoda) 
contains no haemocyanin, and its composition is represented in the 
following table : — 
Chiton. 
Patella. 
Water, 
90-572 
89-972 
Solids, . . . . . 
9-428 
10-028 
f Organic matter, . 
7-820 
8-322 
\ Salts, 
1-608 
1-706 
The gases of the blood of these two Molluscs, investigated by 
means of the mercurial air-pump, gave the following results : — 
Chiton. 
Patella. 
I. 
II. 
I. 
II. 
Oxygen, .... 
12-92 
12-87 
13-21 
12-99 
Carbonic anhydride, . 
30-46 
31-29 
31-52 
31-02 
Nitrogen, .... 
1-36 
1-86 
1-76 
1-81 
* Ray Lankester, Proc. Roy. Soc. Lond., vol. xxi. p. 71. 
+ Jour. Rhys., vol. viii. p. 384. 
t Proc. Roy. Soc. Edin., vol. xviii. pp. 288-294 ; and Jour. Clicm. Soc., 
vol. Ixii. (1892), p. 648. 
§ Concerning the Physiology of Patella, see Dr Griffiths’ papers in Proc. 
Roy. Soc. Loud., vol. xlii. p. 393 ; vol. xliv. p. 328 ; and his hook, The 
Physiology of the Invertehrata, pp. 108, 284 (Reeve & Co., London). 
