CEPHALOPODA. 75 



fleeted ; outer crust thin, by which the nucleus is invested ; 

 nucleus somewhat separable, multilocular, and divided by 

 transverse septa. 



Conilites pyramidata. — The Pyramidal Conilites. 

 Plate X. fig. 25. Pyramidal ; with the concave bands con- 

 tracted. Fossil. 



Genus 30 — HIPPURITES Lamarck. 



Generic Character. — Shell conico-cylindrical, straight, or 

 somewhat arcuated, multilocular, with transverse septa ; 

 having a lateral internal channel formed by two parallel, 

 longitudinal, obtuse and convergent ridges ; the last chamber 

 closed by an operculum. 



Hippurites curva The Bent Hippurites. Plate X. 



fig. 26. Conical, curved, coarse ; lower part truncated 

 and flat. 



Genus 31.— NODOSARIA Lamarck. 



Generic Character — Shell elongated, straight or slightly 

 arcuated, subconic, nodose, consisting of a series of very 

 smooth spherical cells ; the transverse septa perforated. 



Nodosaria Radicula. — The Shining Nodosaria. Plate 

 X. fig. 27. Erect, oblong, and attenuated ; with five globu- 

 lar joints. Two lines long. Inhabits the Adriatic. 



Genus 32.— ORTROCER A.— Lamarck. 



Generic Character. — Shell elongated, straight, or a little 

 arcuated, subconical; externally striated with longitudinal 

 ridges ; chambers formed by transverse septa, perforated by 

 a tube, which is either central or marginal. 

 The shells of this genus resemble a slightly curved horn. 



Orthocera Rapkanus — The Radish-Root Orthocera. 

 Plate X. fig. 28. Erect, elongated, conical, with longitu- 

 dinal continuous ribs ; the joints tumid, the siphon sublateral ; 

 white. Inhabits the Mediterranean sea, 

 g2 



