OFF THE KERMADECS. 281 



expected, as Sir J. D. Hooker states, on all considerations to 

 occur. The soundings of the " Gazelle " and " Tuscarora," have 

 proved that a channel of more than 2,000 fathoms in depth, 

 passes up between New Zealand and the Kermadec Islands. 

 Hence, an ancient land connection cannot be looked to as an 

 explanation of the New Zealand affinities of the Kermadec 

 flora. 



Whilst dredging was going on off the islands, a shark (Car- 

 charias brachyurus), which was attended by a pilot fish (No it- 

 erates sp.) } was caught ; it was, as is commonly the case, covered 

 by a small parasitic Crustacean, a species of Pandarus. Some 

 specimens of this parasite had, curiously enough, a Barnacle 

 (Lepas) attached to them as large as themselves. 



On the shark being skinned, I noticed that a layer of super- 

 ficial or skin muscles extending all over the animal, and only 

 about one-fourth of an inch in thickness, is coloured dark-red 

 by blood-colouring matter (Haemoglobin) , as are all the muscles 

 of Mammalia. .The main internal muscular mass of the shark 

 is pale, almost white. 



Prof. Eay Lankester has described several similar instances 

 of the restriction of the red colouring matter to certain muscles 

 only in animals which possess it.* A closely parallel case is 

 that of the little rish, the " Sea-Horse " (Hippocampus), in which 

 the muscles of the dorsal fin only are red. 



Mr. Lankester accounts for the presence of the Haemoglobin 

 in the dorsal fin muscles only in this case, by the special activity 

 of the fin in question, but such an explanation fails in the case 

 of the shark, the skin of which is apparently immovable ; more- 

 over, the structure of the skin precludes the idea of the red 

 matter beneath it having a respiratory function. 



Mr. Lankester has shown that Hcemoglobin is entirely 

 wanting in one fish at least, the white transparent oceanic 

 surface fish Lep>tocep)lialus, and I believe that small oceanic Flat- 

 fish, Pleuronectids;* will prove also to be devoid of red-blood 

 colouring. 



I was extremely vexed that no landing on the Kermadec 



* E. Ptay Lankester, "On the Distribution of Hcemoglobin." Proc. 

 Royal Soc., No. 140, 1873. 



