NOMENCLATURE. 



29. 



In order that we may be able to distinguish surfaces exact- 

 ly, we must attend to the following expressions. 



Linear {linearis^ § 16.), is, as was formerly remarked, a 

 surface which preserves the same small dimensions through- 

 out, and is every where about the breadth of a geometrical 

 line. 



Orbicular {orbicular is), is a surface which has pretty near- 

 ly the form of a circle. If it deviates more or less from the 

 circular form, it is called roundish, (subroiundus). The term 

 rounded (rotundatus) is also used, when one part of the cir- 

 cumference approaches to the round form. 



Ovate (ovatus), is when a surface is rounded at the base, 

 but tapers towards the apex, and when its length is a little 

 greater than its breadth. 



Elliptical, or oval, {ellipticus, ovalis), is when the length 

 of a surface exceeds its breadth twice or thrice, and it is 

 equally rounded at both ends. (Tab. VII. Fig. 6.) 



Oblong (oblongus), is a surface, the length of which ex- 

 ceeds the breadth more than three times, and which has its 

 ends variously defined. (Tab. VIII. Fig. 2. 5.) 



Lanceolate (lanceolatus), is a surface which tapers gradual- 

 ly towards its apex, and is of considerable length. 



Spathulate (spathulatus), when a surface is rounded at the 

 apex, and tapers towards the base. 



Wedge-shaped (cuneatus, or cuneiformis), denotes proper- 

 ly a surface which terminates in a right line at the apex, and 

 tapers towards the base. It is usual also, without regarding 

 the apex, to designate this tapering alone, under the name of 

 the wedge-sJiaped. 



Tongue-shaped {lingulatus), or band-shaped (ligulatus), 

 denotes a surface of some length, with blunt ends, and paral- 

 lel sides. 



Sword-shaped (ensiformis), is an oblong surface, one mar- 

 gin of which is hollowed, and the opposite one is elevated. 



Sickle-shaped (Jalcatus), is a^ curved surface, one part of 

 which remains straight. 



