132 



acute, the form is heart-shaped (cordatus) (i) ; 2. where the angle is 

 rounded, it is kidney-shaped (reniformis). 



B. A base roundly truncated is rounded (rotundatd) (k). 



C. A base continued down into an angle with convex sides, 1. in 

 a right and larger angle, is obtuse (pbtusa) (I) ; 2. in less than a right 

 angle, is acute (acuta) (TTZ). 



D. A. base terminating in an angle with concave sides is attenu- 

 ated (attenuata) (n). 



All these expressions apply equally to solid and to superficial 

 forms ; but as the latter only can have a margin (margd), the fol- 

 lowing terms are applicable to them alone, being derived from 

 slighter marginal irregularities of figure (fig. 116.), 



A. With acute angles, either projecting or penetrating: 1. 

 where the sides are unequal, the margins are said to be serrate 

 (serratus) (o) ; 2. the sides equal, toothed (dentatus) (p\ The sepa- 

 rate projections in either case are termed teeth (denies). 



B. Where the projecting points are rounded, and the penetrating 

 angle acute, the outline is notched (crenatus) (q), and the separate 

 projections are crenatures (crenaturce). 



C. Where the projecting angle is acute, and the penetrating one 

 rounded, the outline is scooped out (repandus), and the separate 

 projections are teeth (denies). 



D. Where the projecting and penetrating angles are rounded, the 

 margin is sinuate (sinuatus) (s), and the separate parts are termed 

 lobes (lobuli). 



E. Where the projecting and penetrating angles are very acute, 

 and the sections very narrow and long, the outline is ciliate (ciliatus) 

 (i), and the separate parts are termed cilia (cilice). 



