120 Actinopterygii Lopliobrancliii Hemibranchii, fyc. 



Table-case, Acanus is an extinct genns, originally referred to the Berycidae, 

 No. 56. f rom t k e Eocene Slates of Canton Glaris, Switzerland. 



FIG. 164. Saierdia minutus, Ag. ; Eocene, Aixin Provence, France. 



SUB-ORDER, XIII. Lophobranchii, 



These are a small sub-order of bony fishes having the gills 

 not laminated, but in the form of small rounded lobes or tufts. 

 The gill-cover is reduced to a large simple plate ; and the body 

 is more or less encased in hard scales, arranged in segments. 



Here are placed the " Pipe-fishes " and " Sea-horses," which 

 have but few fossil representatives. An extinct species of 

 Siplionostoma is exhibited from the Miocene of Licata, Sicily ; 

 and there is also an ancient type of " Sea-horse " Calamostoma 

 differing from the living Hippocampus in the possession of a 

 caudal fin, from the Eocene of Monte Bolca. Another " Pipe- 

 fish," Solenorhynchus, has been found in the Eocene of Monte 

 Postale. 



SUB-ORDER XIV. Hemibranchii. 



The Fistulariidaa, or "Flute-Mouths," which have been 

 aptly described as " gigantic marine sticklebacks," are first 

 known from the Eocene formation. Fossil remains of the two 

 living genera, Fistularia and Aulostoma, occur at Monte Bolca 

 and in the Slates of Canton Glaris; and Auliscops, another 

 existing form, has been found at Padang, in the Tertiary 

 lignites of the Island of Sumatra. The Monte Bolca deposits 

 also yield two extinct genera, Urosphen and Rhamphosus : the 

 latter has an immense spinous ray, denticulated behind, 

 inserted on the nape, well shown in the specimen in the case. 



SUB-ORDER XV. Plectognathi. 



The Plectognathi are remarkable for their dermal skeleton 

 i __ n __i j i A ~~ .:,, ^-~>^-^./- -4-Vn-k Ganoids " r * ri 



and were originally placed by Agassiz among the 

 account of the characters of their armour. Some 



of 



on 

 these 



