394 INFERIOR OOLITE AMMONITES. 



spinous stages, and less marked more distant costee. This form occurs in the 

 Concaviwn-zone of Bradford Abbas. Its side-view is depicted of natural size in 

 PI. CI, fig. 1 ; the outline of its whorl -section in fig. 2 ; outlines of parts of two 

 septa, fig. 3. 



B. The lateral lobules of L isometric, bipartite. 



\ 



Fig. 31. — Outline of L of Sonn. papilionacea. 



Sonntnia spinosa, 8. Buchman. See PI. LXXXI, figs. 7 — 9, and page 365. 



— quadrifida, S. Buchman. See PI. XCI, figs. 1 — 3, ,, „ 366. 



— papilionacea, 8. Buchman. See PI. XC, figs. 1 — 3, „ ,, 367. 



The above species form the quadrifida-stock (see page 364), and their septation 

 is very remarkable. 



B. The terminal lobule of L becomes slightly intra-axial. 

 A. Lateral lobules of L short and both bipartite. 



Fig. 32. — Outline of L of Sonn. costata. 



a. Lobe narrow-stemmed. 

 Sonninia scalpta, 8. Buchman. See PI. LXXXVII, figs. 1 — 3, and page 376. 



