Dr. J. E. Gray on Lepidosiren. 415 



The Lepidosirens appear to take in water by the nostrils, and at 

 the same time to respire both air as Batrachians and water as fish. 



The generality of the Amphibia, as the Toads, Frogs, and Efts or 

 Salamanders, are organized for aquatic respiration in their young and 

 lower state, and for aerial respiration in their adult condition ; but 

 this animal has both kinds of organs in a state fit for perfect use at 

 the same time, and the animal evidently uses them simultaneously. 



It appears to me that the Mud- fish is much more nearly related 

 to the Amphibia than to any fish that I am acquainted with ; at the 

 same time it evidently forms a particular group in that class. 



Dr. Daniel, who has lived for several years on the Gambia and on 

 Macarthy's Islands, informs me that the Lepidosiren, like the Mud 

 Eel or true Siren, is only found in the rice-fields, which are for more 

 than half the year under water, and that they are only procured by 

 the natives towards the end of the dry season, when they are dug 

 out of the nearly-dried mud. They are eaten fried, and like eels 

 have a rich oily flavour. 



The habit of living in the mud is common to several Amphibia ; 

 thus the Mud-eel, or Siren lacertina, which has lungs and external 

 gills, lives chiefly in mud, being dug out when the ditches of the 

 rice-fields in Carolina are cleared. The Hell-bender or Mud-devil 

 (Protonopsis horrida) and the Congo Snake (Amphiuma), which 

 have internal gills and lungs and a small lateral gill-opening, live 

 sunk in the mud often to the depth of 2 or 3 feet, especially in winter ; 

 and they and the Siren lacertina will live for some time out of water, 

 and are said sometimes to leave it voluntarily. 



Aquatic animals much more frequently bury themselves in the 

 mud than is generally supposed. The common English Frogs and 

 the large Efts bury themselves in the mud during the greater part of 

 the winter, and this also is the casQ with Bytisci and other aquatic 

 insects. 



But some fish also, which have only gills adapted for aquatic re- 

 spiration, have the same habit. Dr. Hancock observes, "When the 

 water is leaving the pools in which they commonly reside, the Yar- 

 row (a species of Esox, Linn.), as well as the round-headed Hassar 

 {Callichthys littoralis), bury themselves in the mud, while all other 

 fishes perish for want of their natural element, or are picked up by 

 rapacious birds. The flat-headed Hassar {Boras costata), on the con- 

 trary, simultaneously quits the place and marches overland in search 

 of water, travelling for a whole night, as is asserted by the Indians, 

 in search of their object. I have ascertained by trial that they will 

 live many hours out of water even when exposed to the sun's rays. 

 Their motion over land is described to be somewhat like that of a 

 two-polled lizard : they project themselves forward on their bony 

 arms by the elastic spring of the tail exserted sideways ; their pro- 

 gress is nearly as fast as a man will leisurely walk." — Zool. Journ. 

 iv. 243. 



" The Indians say that these fishes carry water within them for a 

 supply on their journey. There appears to be some truth in this 

 statement, for I have observed that the bodies of the Hassar do not 



