3. GALEOIDES. 333 



are much less elongate than in Pentanemus : the maxillary is styli- 

 form, and widens very slightly at its posterior extremity ; the inter- 

 maxillary is very feeble, with a slight posterior prominence and 

 with stout processes, and, Hke the mandibula, it is furnished with a 

 narrow villiform band of teeth ; the mandibula has a cleft between 

 the articulary and dentary bones. The vomer is perfectly toothless ; 

 its head has anteriorly two ridges, meeting at a rather obtuse angle, 

 behind which is a shallow groove. The length of the palatine bone 

 is about one-third of the pterygoid ; its outer margin is armed with 

 a narrow band of viUiform teeth. The bottom of the orbit is nearly 

 entirely bony. The praeoperculum is rather narrow, nearly straight 

 in a vertical direction, without a distinct inferior limb ; its inner ridge 

 is very low, not prominent, the muciferous channel rudimentary, and 

 the free margin striated, the striae terminating in a fine serrature. 

 The operculum is triangular, with a slight ridge on its inner surface; 

 the suboperculum is at least twice as large as the interoperculum, 

 and very finely striated. The basal portion of the brain-capsule is 

 neither swoUen nor compressed, and the basisphenoid shows only 

 some pores. The glossohyal is small, styliform ; the ceratohyal 

 moderately elongate. The pectoral appendages are joined to the 

 lower extremity of the radius, which is not particularly w^'d^ ; the 

 openings between the radius and humerus are rather smaU. The 

 two pubic bones do not leave a free space between them, and each 

 is formed by three lamellae, the upper of which is very narrow. 



There are ten abdominal and fourteen caudal vertebra;, the length 

 of the former portion of the vertebral column being to that of the 

 latter as 1 : 1*6. All the neural, haemal, intemeural and interhaemal 

 spines are feeble, except the first interneural of each of the dorsal 

 fins, which is transformed into a bony plate, and the first interhaemal, 

 which has a slight anterior ridge. 



