CYCLOIDEI 



U7 



till, D, and for the correlative elongation of the slender pointed 

 ventral tins. The anal tin, 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 Smerdis. — The species composing this genus are of 

 small size, and are wholly extinct ; they likewise are chiefly 



Fig. 6Q. 



Smerdis minutus (Gypsum of Provence). 



met with in the tertiary ichthyolite beds of Monte Bolca ; but 

 some {e.g., the Smerdis minutus, fig. 60) are from eocene depo- 

 sits in France. In all the species the first suborbital or lacry- 

 mal 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. Gl). It is not 

 represented by any species of older date than the cretaceous 

 epoch ; and both here and in the eocene tertiaries by extinct 



