44 JOHAN KL-EK. JSEC.'ARCT. EXP. FRAM 



HoJoptychiidae. 



Holoptychius Scheii new species. 

 (PI. VIII, figs 3-4). 



In my material there are several scales of a large Holoplyclrius 

 form all from Hie fish horizon at Skrap Valley. Two only of these 

 permit of detailed study. 



Description. A large, broad, elongated scale (S. I. 26), almost 

 completely preserved. (PI. VIII, fig. 3). 



The breadth is 44 mm., lenght 32 mm. As the scale is somewhat 

 incomplete in the anterior portion and on the right side, the actual 

 breadth and length may presumably be estimated at 45 mm. and 35 mm. 

 respectively. The ornamentation of the exposed part consist of regular 

 ribs, about 1 mm. in breadth The two middle ones are sub-parallel, 

 but the others are bent and turn their convex side inwards. They thus 

 diverge towards the back margin. In front these regular ribs are sup- 

 planted by irregular elevations, which are comparatively broader than 

 the ribs. 



2. A little scale (S. I, 23), represented in PI. VIII, fig. 4. It is almost 

 circular with a diameter of about 15 mm. The form and size of the 

 exposed part are unique, for the latter extends at least 11 mm. forwards. 

 The ribs are powerful, and not quite 1 mm. in breadth; they branch 

 out dichotomously forwards. On this scale, too, the outer ribs diverge 

 towards the posterior margin. The original covered portion of the scale 

 is finely grained. 



I) s e r v a t i o n s. These two best preserved Holoptychius scales, 

 and therefore the most minutely described, must undoubtedly be assumed 

 to belong to the same form. It is true, these scales differ considerably 

 as regards size, form and ornamentation, but as A. SMITH WOODWARD 

 points out. the scales vary very much even in different parts of the 

 same specimen. As they entirely agree in the backward diverging ribs, 

 1 refer them to one and the same form. It seems to me that the large 

 scale was situated on the side of the fish, whilst the small one possibly 

 belonged to the dorsal line only. 



To judge from these two scales the Ellesmere form is most nearly 

 related to Holoptychius nobilissimus Ac,. 1 . //. Americctrms, from the 



1 A. SMITH WOODWARD, Notes on Some Upper Devonian Fisli Remains in East 

 Greenland. (Bih. K. Sv. Vet. Akad. Handl. 26, IV, No. 10, 1900, page 6). 



