Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia. 421 



posteriorly, is 0-018 m. The anterior margin is nearly straight, the upper and 

 lower margins slightly convex, whilst the posterior one is more or less crenulated. 

 The scales appear to have been very thin near the posterior margin, and conse- 

 quently easily broken. Most of the specimens are imperfect. The surface is 

 striated, the striations extending parallel with the upper and lower margin of the 

 scale, whilst a second series radiate from the middle of the anterior surface of the 

 scale, and extend to the posterior margin (fig. 19). Other scales are more or 

 less oval in outline, with concentric rings over the greatest portion of the surface, 

 the posterior part of the scale, which was uncovered by succeeding ones, being 

 striated (fig. 20). The greatest diameter is 0'03 m. 



These scales appear to resemble most closely those of Hoplopteryx letvisiensis, 

 Mant. {Beryx ornatus, Ag.), and, whilst there is insufficient material to form a 

 species, there can be no hesitation in including them in the genus Hoplopteryx. 



Formation and Locality. — Etage Danien (zone with Anancites sulcatus, Groldf.) : 

 Saltholm Limestone ; Limhamn, Scania. 



Fx coll. — Geological Museum, Lund University. 



Hoplopteryx viiiior, Davis. 

 (PI. XLV., figs. 3 and 4.) 



A number of specimens of a small species of Hoplopteryx from the chalk of 

 Limhamn occur in the collections at the Riksmuseum at Stockholm. They are all 

 imperfect, and afford only a small amount of information as to their characters 

 and structure. The head, and a portion of the vertebral column, is all that is 

 preserved. The head, from the tip of the snout to the posterior margin of the 

 gill-cover, is 0-05 m., and the height of the head 0*04 m. The orbit was probably 

 large. The gill-cover consists of the pre-operculum (p. op.), a long bone, with 

 a, crenulated margin; the operculum (o/j.) is imperfect, the anterior margin 

 slightly concave, the upper margin rounded, and the remaining part along the 

 posterior margin inclined to the inferior anterior extremity, so as to form an 

 irregular triangle. The inter- operculum is not preserved ; but a detached bone 

 has the appearance of being the sub-operculum (s. op.). The mandible (m.) is 

 attached at its posterior extremity to a triangular bone, the quadrate (q.). The 

 mandible is strong, deep behind, the dentary portion bearing a number of small 

 teeth. The maxilla (?«.r.) and pre-maxilla (p.-mx.) may also be distinguished, 

 but the dentition of the latter is not defined. Other bones may be distinguished 

 on the anti-orbital and inter-orbital regions of the head. 



A portion of the vertebral column is preserved. It extends to a distance of 



303 



