No. l8.J TRIASSIC FISHES OF CONNECTICUT. 57 



of the State Geologist of New Jersey for 1904. A reconsidera- 

 tion of its characters, however, especially the remote position 

 of the dorsal fin, and the appearance of the squamation and oper- 

 cular plates, leaves little room to doubt that its affinities art 

 with Dictyopyge. Nor does any good reason appear for doubt- 

 ing the trustworthiness of the record of the locality whence the 

 specimen was derived. The micaceous grains in the matrix are 

 a characteristic feature of the Connecticut Valley sandstone, and 

 the general appearance of the rock is wholly dissimilar to the 

 prevailing type of deposit occurring either in New Jersey or 

 Virginia. For the present, therefore, the evidence of this speci- 

 men must be accepted as proving the presence of Dictyopyge in 

 the Connecticut Valley area. 



Suborder ProtospONDYLI. 



In this suborder, as distinguished from Paleozoic and early 

 Mesozoic Chondrosteans, the median fins become absolutely com- 

 plete, in that each separate ray has its own individual sup- 

 port. At the same time the upper lobe of the tail is considerably 

 shortened, so that the caudal fin forms a flexible fan-shaped 

 expansion at the blunt end of the body. The members of this 

 suborder chiefly characterize the Triassic and Jurassic periods, 

 and exhibit endless variety; but their sole survivors at the 

 present day are the long-bodied garpike {Lepidosteus) and bow- 

 fin (Amia) of American fresh waters. 



Family SEMIONOTID^. 



Trunk more or less deeply fusiform, rarely cycloidal. Cranial 

 and facial bones more or less robust, and opercular apparatus 

 complete. Gape of mouth small, teeth styliform or modified for 

 crushing. Notochord persistent, vertebra not more than rings. 

 Fin-rays robust, fulcra large, dorsal fin not extending more than 

 one-half the length of the trunk. Scales rhombic, except oc- 

 casionally in the caudal region. 



Genus Semionotus Agassiz. 

 (Syn. Ischypterus Egerton.) 

 Trunk fusiform. Marginal teeth slender, conical, somewhat 

 spaced, inner teeth stouter ; opercular apparatus well developed. 



