THE MOJlMVfUIDiK, NOTOl'TEftn;^, AND iiY.OUONtlDJFj. 209 



large. There is no diHtinct aogular bone. The dcntary is well 

 toothed, the larger teeth being situated on the labial and lingual 

 edges, the smaller teeth occupylnj^ the space between these 

 two rows. 



Jlyopalatine Series {?ig. 22). — The hyoraandibular articulates 

 with the cranium by two distinct heads ; its opercular head is 

 long, and its axis slopes downward and backward. The angle 

 between the symplcctic and the axis of the hyoraandibular is a 

 little over a right angle. Teeth of fair size occur on the 

 palatine and ectopterygoid, and small teetli on the middle part 

 of the entopterygoid. The ectopterygoid is slightly curved, but 

 has no distinct angulation. 



Opercular Series (figs. IS and 22). — The opercular and sub- 

 opercular bones are rather wmall as compared with the siz-e of 

 the skull. The branchiostegal rays are nine in number on each 

 side. Six are attached to the ventro-external edge of the 

 ceratohyal, one at the junction of the ceratohyal with the 

 epihyal, and two on the epihyal. They form an evenly graduated 

 series, 



Ilyohranchial Series. — The sides and upper surface of the 

 remarkably large glossohyal consist of ectosteal bone. Examined 

 from below, the anterior three-fourths of the interior are seen to 

 be composed of cartilage, the posterior fourth ef cartilage-bone. 

 The latter is situated at a higher level tlian the first basi- 

 branchial, and overlaps the anterior two-thirds of that bone. 

 The glossohyal bears the largest teeth in the head ; the large 

 teeth occupy the edges of the upper surface, and the inter- 

 vening space is occupied by small teeth. The parasphenoid 

 teeth fit very neatly between the large glossohyal teeth, and 

 form a prehensiye apparatus from which there can be little 

 escape. 



A dentigerous membrane-bone covers the whole of the second 

 basibranchial, the posterior third of the first basibranchial, and 

 the anterior three-fourths of the third basibranchial. It forms 

 a direct continuation of the dentigerous part of the glossohyal. 

 The upper and lower hypohyals are approximately equal in size 

 and are rather large. The urobyal, on the other hand, is small 

 and short. 



The third epibranchial has an ascending process, but the first 

 and second have not; the second and third pharyugobranchials, 



LINN. JOTJEN. — ZOOLOGY, VOL. XXIX. 15 



