LEPTON. 171 



LENTICULAR. (Lens.) Of a circular, convex form, as Pectun- 

 cuius, fig. 134. 



LENTICULINA. Lam. A genus of microscopic Foraminifera. — 

 Descr. Lenticular, sub-discoidal, compressed, convolute, sym- 

 metrical ; aperture notched ; chambers few in number ; visible 

 on the exterior, radiating from the centre of the disk. 



LEPADICEA. Bl. The first family of the class Nemantopoda, 

 Bl. This family consists of the same animals which constitute 

 the Pedunculated Cirripedes of Lamarck, and part of the genus 

 Lepas in the system of Linnaeus. It contains the genera 

 Gymnolepas, Pentalepas, Polylepas and Litholepas. 



LEPAS. (Af7rae, lepas, a rock.) The Linnsean name Lepas 

 contains all the Cirripedes or Multivalves, the different kinds of 

 which are not distinguished in the accounts given by early 

 writers of the habits of the animals. (Fig. 14 to 43.) It was 

 formerly applied to the Limpets or Patella. In fact, the ancient 

 definition was ** Concha petrae adhserens," and would apply to 

 any shells attached to rocks. 



LEPTJENA. Dalman. A genus belonging to the Brachiopoda ; 

 and thus described : — ' ' Hinge compressed, rectilinear, frequently 

 exceeding the width of the shell.' ' It forms part of the genus 

 Producta, Sow. Fig. 206, L. depressa. 



LEPTOCONCHUS. Ruppell. (Aevtos, leptus, thin ; Koy X oc, 

 conchos, shell.) This shell resembles a young Magilus in general 

 appearance, although the animal is said to differ. In the young 

 Magilus also, the inner lip is reflected over the body whorl, which 

 is not the case in Leptoconchus. Red Sea. Fig. 11. 



LEPTOCONUS. Sw. A sub-genus of Conus, consisting of Conus 

 grandis, amadis, duplicatus, Australis, &c. Sw. p. 312. 



LEPTOLIMNEA. Sw. A sub-genus of Limnea, described as being 

 nearly cylindrical. Limnea elongata, Sow. Gen. fig. 6. 



LEPTON. Turton. Solen Squamosus, Montague, and other species 

 described as "flat, nearly orbicular, equivalve, inequilateral, a 

 little open at the sides. Hinge of one valve with a single tooth, 

 and a transverse linear lateral one on each side ; of the other 

 valve, with a cavity in the middle and a transverse deeply cloven 



