Forcibly suggestive are such facts of still further undiscovered denizens of the deep! And as to _what_ they are, fish, mammal, or reptile, or a compound of either two or all three of these, why doubt _any_ possibility when we know that on land are similarly complicated organisms which so lately have perplexed our most able physiologists? Take, for example, that curious anomaly, the mud-fish of the Gambia, _Lepidosiren_, referred to in the last chapter, and which, to look at, is as much like a lizard as a fish, with its four singular appendages where either legs or fins might be. Again, we have that paradox in nature—bird, reptile, and quadruped combined—in the Australian _Platypus_, a semi-aquatic animal. ‘These two fresh-water animals are,’ says Darwin, ‘among the most anomalous forms now found in the world; and like fossils, they connect, to a certain extent, orders at present widely sundered in the natural scale.’[76] Other equally remarkable links between the various groups might be cited to prepare us for any marine anomalies which may hereafter surprise us. Taking into consideration, also, that many of our smaller aquatic animals have their representatives on a huge scale in the ocean, why should there not be gigantic ophidian forms to correspond with the terrestrial pythons and anacondas? As in point of size salt-water fishes exceed those of our rivers, and as the enormous marine mammalia exceed those on land, we might the rather wonder if there were not _one_ ‘great sea serpent,’ but many unsuspected species of reptiles, compound ophiosaurians, or saurophidians, or who shall say what, in those inaccessible depths. ‘How is it none have ever been captured?’ it is asked. In reply, Has any one ever captured a swiftly-retreating land snake escaping pursuit? Who can overtake or circumvent it when in its tropical vigour? And how vastly must the powers and swiftness of those immense pelagians exceed the kinds with which we are familiar! ‘Then, Why have no bones been found?’ Mr. Bartlett’s reason is one of those assigned, and in addition I may suggest that the love of locality, so strong in land reptiles, may also exist in marine ones, which probably retire to the recesses of their submarine habitats to die. ‘How is it none have ever been killed?’ Well! A cannon ball on the instant, and not much less, would be required to ‘kill it on the spot,’ as some have sagely recommended. Mr. Henry Lee, among others, does not regard capture as impossible and in support of my own speculations—more correctly speaking _imagination_, perhaps—I give the concluding words of his paper:—