CTENOIDEI. 



171 



fiiis. The anal fin, A, is much shorter than the dorsal. Owing 

 to the soluble nature of the scales, and to the well-ossified 

 skeleton, the fossils of this, as of most other tertiary fishes, 

 are exemplified by the vertebral column and skull more than 

 by the skin. 



Genus Smekdis— The species composing this genus are 

 of small size, and are chiefly met with in the tertiary ich- 



Fig. 78. 

 Smerdis minutus (Gypsum of Provence). 



thyolite beds of Monte Bolca; but some (e.g., the SmerdAs 

 minutus, fig. 78) are from eocene deposits in France. In all 

 the species the first suborbital or lacrymal bone is strongly 

 dentate, as is also the preoperculum ; but this has no spine 

 at the angle. The operculum terminates behind by a rounded 

 prominence. There are two dorsals. The scales are minute, 

 but are occasionally preserved. 



Sub- Order 2.— CYCLOIDEI. 



This sub-order includes the teleostian fishes with undivided 

 and unjointed spines at the fore part of the dorsal, and with 

 smooth flexible circular or elliptical scales (fig. 79). It is not 

 represented by any species of older date than the cretaceous 

 epoch; and both here and in the eocene tertiaries by ex- 



