No. l8.] TRIASSIC FISHES OF CONNECTICUT. 45 



The type and only known species, attaining a total length of 

 about 70 cm. to the tip of the supplementary caudal fin, and 

 maximum depth of trunk about 20 cm. Anterior dorsal fin 

 strong, supported by a single large laminar axonost; the lobate 

 posterior dorsal nearly opposite the anal, and corresponding to 

 it in form and size. Caudal fin much elongated, and separated 

 from the supplementary caudal by a distinct interval. Paired 

 fins obtusely lobate. Scales large, cycloidal, and deeply over- 

 lapping ; the exposed portion marked with fine longitudinal rugs ; 

 teeth unknown. 



This large Crossopterygian is of extremely rare occurrence, 

 being known by a scant half-dozen individuals, of which two, in- 

 cluding the type, were obtained from near Boonton, New Jersey, 

 and the others, very imperfect, from Durham, Connecticut. Most 

 of the remains are now preserved in the American Museum of 

 Natural History in New York, but there is one distorted ex- 

 ample of the lower jaw in the Museum of Wesleyan University 

 at Middletown (Cat. No. 846), which was collected by Mr. 

 S. W. Loper from the anterior shales. Unfortunately this speci- 

 men shows no satisfactory indication of teeth, but appearances 

 are at least suggestive that these were slender and conical. The 

 external surface of the bone is finely granulated. 



Order ACTINOPTERYGII. 



Paired fins non-lobate, having an extremely abbreviated en- 

 doskeletal portion, and the dermal rays prominent. Caudal fin 

 abbreviate-diphycercal, heterocercal, or homocercal. A single 

 paired series of transversely elongated rays, with or without an 

 anterior azygous element, developed in the branchiostegal mem- 

 brane between the mandibular rami. 



Suborder ChONDROSTEI. Sturgeons. 



In these fishes, the oldest and most primitive of the Actin- 

 opterygii, the notochord is more or less persistent, the supports 

 of the dorsal and anal fins are less numerous than the dermal 

 rays apposed to them, the paired fins more abbreviate than in 

 the Crossopterygian order, and the tail is completely heterocer- 

 cal. Primitive sturgeons differ also from the fringe-finned 



