JO CONNECTICUT GEOL. AND NAT. HIST. SURVEY. [Bull. 



species, each fin having sometimes twenty or more. Length of 

 the longest fulcrum of the dorsal fin nearly equalling one-half 

 that of the anterior margin of the fin. 



In the original description of S. ovatus by William C. Red- 

 field, it is stated that " it exceeds all the known American species 

 in the comparative width or roundness of its form, and is also 

 remarkable for the large size of its scales. It is of rare occur- 

 rence, and, owing probably to its great thickness, is seldom ob- 

 tained in a perfect form." The younger Redfield, commenting 

 on the same species in 1854, pronounced it " the broadest and 

 most ovate species of Palcconiscus that is known," and added 

 further, that " in size of the scales it resembles P. Agassizii, but 

 its form will readily distinguish it/' That is to say, the squama- 

 tion is heavy, but the flank-scales are relatively deeper than in 

 S. agassizii, and the form is also deeper-bodied, or more ovate. 



The Redfields, father and son, and also Newberry, agree in 

 claiming for this species a distribution in both the Connecticut 

 Valley and New Jersey Triassic basins. With this species New- 

 berry also identifies a fragmentary individual from the Triassic 

 Coal-field of Virginia, originally referred to Tetragonolepis by 

 Sir Philip Grey Egerton. -Noteworthy is the fact that all the 

 more perfect examples have been obtained from a single locality 

 near Boonton, New Jersey, and the recognition of this species 

 in outlying areas depends upon the evidence of unsatisfactory 

 material. The present writer has thus far failed to discover a 

 single undoubted example of the species in question from the 

 Connecticut Valley Trias, yet this is by no means equivalent to 

 saying that its remains do not occur in this region. It may per- 

 haps be worth mentioning that in the Museum of Wesleyan 

 University is preserved the anterior half of a deep-bodied fish 

 (Cat. No. 869) whose specific relations cannot be accurately 

 determined. It is labeled as belonging to 5". gigas, a " species ' 

 which can be maintained only in a provisional sense. The so- 

 called Semionotus robustus of Newberry is but little better 

 known, and is doubtfully distinct from 5. ovatus, which it ap- 

 proximates in size. A certain resemblance between the published 

 figure of S. robustus and the imperfect deep-bodied specimen at 

 Wesleyan University just referred to cannot be denied. Further 

 evidence, however, is necessary before we can positively affirm 

 the presence of S. ovatus in the New England area. 



