54 TRIASSIC FISHES AND PLANTS. 
or quadrate, sometimes twice as high as long, surface partially covered with 
raised lines which project to form teeth on the posterior margin, In the 
middle of the body the scales are longer than high, plain or faintly striated, 
and bearing one or more posterior teeth; scales near tail rhomboidal, 
smooth; scales of median line of back transversely oval or somewhat polyg- 
onal, faintly striated; teeth numerous on premaxillaries, maxillaries, and 
mandibles, from one-eighth to one-quarter of an inch long, conical, sub- 
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acute. The average size of the fish of this species may be said to be nine 
inches in length by three in breadth. he general form and proportions 
were similar to those of our shad and the outlines were equally elegant. As 
we always find the fishes of this species lying on the side, we may infer 
that, they were laterally compressed, the vertical diameter being greater 
than the transverse. 
The specimens for which Sir Philip Egerton suggested the name now 
given were from Durham, Conn., and this seems to be the special home of 
the species, though it has apparently been found at other localities in the 
Connecticut Valley and in New Jersey. Fully one-half of all the fishes 
obtained by Mr. Loper at Durham belong to this species, and he has fur- 
nished me with a large number of beautifully preserved specimens. 
As in all the species of the genus the head seems to have been largely 
cartilaginous, and as’ a consequence is often defective or distorted in the 
fossils. Occasionally, however, as in the specimen represented in Fig. 1, 
on Plate XV, the outline of the head is accurately shown as well as the posi- 
tion of the eye and the form of several of the head bones. But even here 
they are somewhat confused, and it is difficult to compare bone by bone 
the structure of the head with that of the palzoniscoid fishes of the Car- 
boniferous, with which the relationship has been supposed to be close. So 
far as we can judge from the specimens before us branchiostegals are want- 
ing, the operculum is nearly vertical, and the eye surrounded by a bony 
ring composed of two pieces. Unfortunately the head bones are not only 
generally displaced, but they are covered with a coating which obscures 
the sutures, the matrix clinging to the granulated surfaces of the head 
bones much more closely than to the polished scales. 
