2G0 Dr. K. II. Tia(|uair on Fossil Fiahea 



scales of the Hank, are subpurallel aiul run more or less verti- 

 cally down the scale, or between the two acute angles (fig. 9) ; 

 on the scales ot" the back, however, they often follow a more 

 irregular and tiexuously contorted course (fig. 11). 



The general contour of the iish, too, as shown in the figure 

 illustrating my previous paper, differs considerably from tliat 

 in Fi/(ppterus. In such typical Fi/i/cpteri as F. mandihtdaris 

 or F. JIu)/d>oldtii\ both dorsal and anal tins arc placed much in 

 front of the caudal ; the dorsal is not jtarticularly large for the 

 size of the tish (in fact none of the fins are, save the caudal, 

 which is truly tremendous) ; but the base of the anal is jiecu- 

 liarly extended backwards. On this latter peculiarity Agassiz 

 dwells })articularly in characterizing the genus ; for he says, 

 " mais ce qui caracterise plus particulierement les Fi/</nptems, 

 c'est qu'a cette caudale incquilobe se joint une anale fort longue 

 qui garnit le bord inferieur du corps sur une grande etendue"*. 

 In Xematoptydiius Greenockii, on the other hand, the d(jrsal and 

 anal are considerably larger in proj)ortion, and ])laeed nearer 

 the tail, and the anal fin may be said to be the exact counter- 

 part of the nearly oppositely placed dorsal. Other fishes have 

 indeed been named " Fi/goj)terus,^^ in which the peculiar cha- 

 racter of the anal fin referred to is also absent, as, for example, 

 in the very imperfectly known F. BKcklandi of the Burdie- 

 house Limestone, of Avhich Agassiz says that it is characterized 

 by having its anal " tres-rapprochoe de la caudale "t- What- 

 ever value, however, we may be inclined to place on the form 

 and position of these fins in a more extended revision of the 

 genus Fi/fjopteruSj the form of the scales alone is certainly 

 abundantly sutficient to distinguish Xetiuitopfi/c/u'itfi generieally, 

 not only from Fyyojjterus^ but from all the other known genera 

 of the family of Palreoniscidie. 



In my former communication the teeth were imperfectly de- 

 scribed, it being very ditiicult to obtain satisfactory views of 

 them in the Wardie specimens, owing to the hardness and 

 peculiar nature of the ironstone in which they are enclosed. 

 Specimens from Loanhead, however, preserved in soft bitumi- 

 nous shale or in cannel coal, aflbrd better oj)portunities for 

 studying their configuration (PI. XVI. fig. 8). They are 

 acutely conical, round in transverse section, and more or less 

 curved inwards. Their apices very distinctly display the well- 

 known *' enamel cap " clearly marked off on the exterior of the 



* Poissons Fossiles, t. ii. pt. 2, p. 74. 



+ lb. p. 77. I canuot refrain Ironi expro&siii<r very coii^itUrablt doubts 

 as to that siu'cics, or, in fact, any other of the so-callccl Carboniferous 

 " ri;ijoj}f(n\' bcinj: really referable to that genus. 



