152 THE VICTORIAN NATURALIST. 



flattened and not compressed from side to side as nearly all the 

 Amphipods are ; the antennse also of Iphiplateia are peculiar. We 

 spent the night lying comfortably off Sorrento, and from the shore 

 in the morning we collected some sand-hoppers, which I find 

 belong to a new species of Orchestia. 



The following morning we steamed up the South Channel, and 

 commenced work near the Channel Fort, above Wilson's stations, 

 8 and 9, and worked downwards through them, and nearly to 

 the mouth of Symond's Channel. The depth of water near where 

 we commenced work reaches in places 20 fathoms, but varies 

 considerably between that and 12 fathoms; lower down again, at 

 about the middle of station 8, it is only 7 fathoms, and this depth 

 is about the average for the remainder of the way. The character 

 of the bottom, which is mostly of clear coarse sand and broken 

 shells, combined with the depth of water, made hauling up the 

 dredge very heavy work. 



The most prominent form brought up was the interesting little 

 Lancelet (Amphioxus), which was present in great numbers in 

 every haul to nearly as far as Symond's Channel. As is well 

 known they are worm-like, primitive vertebrate animals, about two 

 inches in length, and of semi-transparent and slightly iridescent 

 colour, structurally agreeing with fishes by the walls of the 

 pharynx possessing many gill-slits modified for respiration, but 

 widely differing from them and the higher animals by the want of 

 a specially differentiated brain and other features. They swim 

 rapidly, and are able to live for an hour or more out of the water. 

 Sufficient water, no doubt, is contained in what is known as the 

 atrial cavity to enable them to sustain life. They were most 

 active on deck by frequently adopting a series of vigorous skipping 

 movements. We had dredged them before in Western Port, but 

 there the locality where they are found is not so extended as in 

 this bay. Amongst them were a considerable number of an errant 

 Chaetopod worm, nearly 2 inches long, closely allied, if not iden- 

 tical, with the genus Ammotrypane, of a pearly colour, and 

 resemble the Amphioxus in general appearance. I mention 

 this, for in Western Port 1 found the same worm together with 

 Amphioxus. No doubt they enjoy the same habitat, and I do 

 not mean to suggest any causal relationship, but it has been 

 noticed in the northern hemisphere that Ophelia, a genus very 

 near to the above, is found with Amphioxus. 



After lunch we visited the Pope's Eye Beacon, and later 

 worked a considerable area at the entrance of Symond's Channel, 

 in and somewhat outside of Wilson's station No. 6. The 

 depth is between 6 and 9 fathoms, and the bottom mostly sandy 

 and rich in general material, such as sponges, worms, echino- 

 derms, and crustaceans. Amongst many interesting forms I may 

 mention a particularly large specimen of a twelve-plated shield 



