Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia. 419 



the position and sequence of the mandibulary susijensorium composed of the 

 hyomandibular (A), the symplectic, the quadrate, and the metapterygoid, 

 the latter connecting the suspensorium with the pterygoid and the ento- 

 pterygoid. The hyomandibular {hyo.) is largely expanded in its upjjer portion ; 

 its lower portion is contracted and partially hidden by the pre-operculum ; joined 

 to the hyomandibular in descending series is the symplectic or mesotympanic 

 (spn.), which connects with the quadrate (qu.), to which the lower jaw is attached. 

 The metapterygoid (mj^t.) is a large, flat bone filling the space between the 

 hyomandibular, the symplectic, and the quadrate, and connects them with the 

 pterygoid {j)t.) and the entopterygoid {ejyt.). The pterygoid is joined at its 

 anterior extremity to a bone, which increases in size forwards, and which is prob- 

 ably the palatine {pal.). Attached to this bone are numerous teeth similar to those 

 of the pre-maxilla. The palatine is also exhibited by the specimen represented by 

 fig. 2, and on this also small teeth may be distinguished. The branchiostegals 

 are exhibited in fig. 1. ; they are long, curved bones, tapering at the distal 

 extremity to a point. 



The spinal column consists of thirty vertebrae, of which sixteen are caudal. 

 The vertebrae are large and robust, O'OOZm. in height under the anterior rays of 

 the dorsal fin, and 0-006 m. in length. Large haemal and neural spines, with 

 forked bases, are attached to the vertebrae. Connected with the haemal spines, 

 inter-spinous bones support the anal fin ; whilst more numerous inter-spinous bones 

 connect the neural spines with, and support, the dorsal fin. The ribs are long, 

 and of considerable strength. A short distance below the vertebral column the 

 ribs are crossed by a series of stylets or epiplural bones 0*015 m. in length. 



The dorsal fin commences immediately over the scapular arch, and extends a 

 distance of 0'09 m. along the dorsal surface. It is separated from the caudal fin 

 by a space of 0'03 m. The anterior portion of the fin consists of a series of 

 spinous rays, ten in number; the sixth from the head is the largest, being •025 m. 

 in length, those before and behind diminishing gradually in size ; the most 

 anterior ones are short, rudimentary rays. All the rays are thick and strong, 

 sharply-pointed, and inclined, with a slight curvature, backwards. Eight or ten 

 articulated rays succeed without intermission the spinous ones ; they are longer 

 than the spinous rays, and divided towards the distal extremity into filaments. 

 The anal fin commences opposite the anterior rays of the soft part of the dorsal 

 fin, and extends backwards to a length of about 0-04 m., and appears to be 

 separated from the base of the caudal fin by 0-03 m. ; but this part of the body is 

 not well preserved. The anterior rays of the anal fin, apparently three in number, 

 are spinous ; the posterior one is longest, equally strong and similar in form to the 

 spines of the dorsal fin. The anal fin spines are supported by strong inter-spinous 

 rays, widely expanded at the distal extremity, where attached to the fin rays. 



IRAN'S. KOr. DOB. SOC, N.S. VOI. IT., PAD.! VI. 3 



