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developed, oblong ; interoperculum square-shaped ; no subopercu- 
lum. Branchiostegal rays numerous ; the anterior one of each 
lateral series broader than the rest a median lozenge-shaped plate 
in front. Jaws stout ; teeth acutely conical, sharp, of two sizes, 
large and small, the larger ones being placed in a row internal to 
the more closely set outer series of smaller teeth. Ornament of 
cranial bones tubercular or rugose-tubercular; facial bones, and 
those of the shoulder-girdle striated; the jaws usually also tuber- 
culated just at the dental margin. 
The name Elonichthys was first proposed by Giebel* for certain 
fishes ( E . Germari , crassidens and loevis) from the coal-measures 
of Wettin, near Halle, which he considered intermediate in generic 
character between Amblypterus and Palceoniscus, as defined by 
Agassiz. They were said to resemble Palceoniscus in their ful- 
crated fins, but to differ from it in the absence of the scaly covering 
to the rays, affirmed by Agassiz to exist in some Palmonisci, while 
to certain “ Amblypteri ” they showed an affinity in the striation 
of their scales, and to “Amblypterus" in general in the large size of 
the fins. Their special characteristics were to be found in the 
dentition, which consisted of an external series of minute teeth 
comparable to the “ Biirstenzahne 1 of Amblypterus , between which 
there were large conical teeth, “ wie ich dieselben weder bei den 
Palasonisken noch Amblypteren finde.” Unfortunately, however, 
for this diagnosis, the fin-rays of Palceoniscus are no more covered 
with scales than those of any other genus belonging to this family; 
nor are the fins of Agassiz’s “ Amblypteri ” destitute of fulcra 
except on the upper lobe of the tail,” as has been so repeatedly 
stated by compilers, who, copying this error from the “ Tableau syn- 
optique des Genres et des Especes” have apparently overlooked the 
correction of it made by Agassiz himself a few pages further on in 
his general description of the genus.f The dentition, too, of Gie- 
bel’s Elonichthys is essentially similar to that of Agassiz’s Ambly- 
terus macropterus ( Bhabdolepis Troschel) in which large conical 
teeth were shown to exist by Goldfuss in 1847,J and again by 
* Fauna der Vorwelt, 1, 3, p. 249. 
t Poissons Fossiles, vol. ii. pt. 1. p. 29. 
+ Beinage zur vorweltlichen Fauna des Steinkohlen-gebirges. Bonn 1847, 
p. 20. 
