424 THE AMERICAN MONTHLY [Dec. 



occipital to the frontal; which in its turn meets the ntes- 

 ethmoid; which encloses the cranium in front. Thenasal 

 projects beyond this and over the nose. In the side of 

 the cranium encasing the ear are located a number of 

 bones collectively called the peri-otic bones, and in front 

 of these a small bone, the alt- sphenoid, lies in the side 

 wall of the cranium. The orbit is bounded by a ring of 

 small sub-orbiial bones, and a supra-orbital is located above 

 and behind it. The lower jaw is articulated at the end 

 of a. row of bones which run up to the side of the hinder 

 part of the skull, these are the quadrate at the articula- 

 tion; the symplcctic above it and the Jiyo-mandibidar still 

 above and articulating with the skull. The sides of the 

 roof of the mouth articulate with this row of bones by 

 means of the palatine in front and the pterygoid behind; 

 the pterygoid being made of three separate parts: the 

 pterygoid proper and above it the meso-pterygoid and be- 

 hind these and in front of the symplectic the ineta-ptery- 

 goid.^ 



16. The Skin. — Keeping the skin moist, examine it 

 closely, using the point of a needle, notice: that it is 

 covered generally with scales; that these are arranged in 

 regular alternating series (the number of rows is defi- 

 nite for each species of fish), that each scale is free from 

 the skin behind but attached in front so as to offer no re- 

 sistance to motion in that direction; that the scales near 

 the middle of each side from the head tailwards, show a 

 marking, lateral line, not present in the rest of the scales. 

 Remove a single scale from the body surface anywhere 

 not in the lateral line, keeping an exact idea of its posi- 

 tion in the body as to outer and inner surface and anterior 

 and posterior borders. Mount and examine the scale dry, 

 noting its shape as to outline, the absence of notches on 

 the margin and the presence of concentric markings, 

 whose center is not the centre of the scale, (cf. cycloid 



