SCIENTIFIC SURVEY. 37 



CuiRASSED — Covered with shield-like covering or scaly plates. 

 CuLDESAC — The bottom of a bag ; an appendage to the stomach or 



intestines, like a small bag or sac, with no opening except the 



passage into it from the stomach. 

 Cycloid — A peculiar curve or circle formed by any point in a circle 



while it is rolling on a plane surface as does a carriage wheel. 

 Cycloidal — Pertaining to or resembling a cycloid. 

 CYCLomiANs — The fourth order of Agassiz system of Ichthyology 



containing those having circular smooth edged scales, as the 



herring. 



D. 



Deciduous — Falling ; when applied to the scales of fishes it means 



those that adhere but slightly and fall easily. 

 Dentary — The place or places where teeth are inserted. 

 Denticulated — Having small teeth. 

 Dermic — Skinny ; pertaining to the skin. 

 Dermopteri— Skin fins ; (from derma, the skin, and pteron, wing 



or fin ;) the tenth order of fishes in some systems. 

 Dichotomized — Separated into two forks or branches, 

 DiPHYLLOus — Divided into two-leaf like divisions. 

 Discoid — Having the form of a disc. 

 Dorsal — Belonging to the back. 

 Ductus pneumaticus — A tube or passage by means of which the air 



bag communicates with the throat. 



E. 



EcHENEis — (Sucking fish,) or a fish that often attaches itself to 



ships; from Greek eko, I have, and naos, ship. 

 Emarginated — Notched on the margin with circular notches. 

 Enoplus — Armed ; from Greek enoplos, armed. 



P. 



Fins — The organs of motion and position of fishes. They are 

 formed for the most part of a membrane spread over a number 

 of rays which are either bony or cartilaginous and which are 

 jointed, and thus expand or fold up the membrane at the will of 

 the fish. They are considered by comparative anatomists to be 

 analagous to the wings of birds, or the arms and feet of mammalia. 



