74: GUIDE TO THE AUSTRALIAN MUSEUM. 



out ; many genera frequent our seas, the best known being the 

 Pipe-fish (Syngnathus) and the Sea-horses ( Bippocam'pus and 

 SohjwgyiathusJ, while the most curious form is the Phijlloideryx, 

 which has its Ijody ornamented with long leaf-like filaments, 

 resembling the fronds of seaweeds and serving as a disguise. 



Order FLEGTOGNATHI, in which the skeleton is incom- 

 plett.'ly ossified, and the vertebne in small numbers ; it contains 

 two families only, (1) the Sclerodermi, which includes the File- 

 fishes (Baliiites), the Leather-jackets {Monacanthus), many of which 

 are excellent eating, and the Box-fishes {Ostracion) which are 

 almost entirely covered by a bony carapace ; and (2) the Gymno- 

 dontes, to which belongs the Toados {Tetrodon) of which the flesh 

 of many species is poisonous, the Porcupine-fish [Dicotylichthys), 

 and the Sun-fishes (Orthayoriscus). 



The third sub-class, called CYCLOSTOMATA on account of 

 the mouth being surrounded by a circular lip which forms a 

 suctorial organ, contains the Lampreys, of which two genera are 

 found in the colonies, viz. Mordacia from Tasmania, and Geotria 

 from South Australia. Both genera, as with Galaxias, are found 

 in Chili. 



The fourth and last sub-class, the LEPTOCARDII consists of 

 but one family Cirrostomi, and two genera Branchiostoma with two 

 and Epigionichthys with one Australian species ; they are without 

 ribs, brain, jaws, or heart, and have, not without justice, been 

 separated from the true fishes altogether. 



» 



Typical specimens of all the genera contained in the Museum, 

 will be found in Cases 16a, 16b, and 16c in the Australian Hall, 

 Ground Floor. 



