THIRD, OR VERMICERAN BRANCH. LOT 
Caloceras Johnstoni, Hyarr. 
Amm. Johnstoni, Sow., Min. Conch., p. 464, pl. eccexlix, 
Amm. torus, D’OrB., Pal. Francaise Ceph., p. 212, pl. liii. 
Amm. psilonotus plicatus, Qurenst., Amm. Schwab. Jura, pl. i. fig. 12, 13. 
Amm. Johnstoni, QuENs’., Ibid., pl. i. fig. 20. : 
4ligoc. Johnstoni, Wricut, Lias Amm,, pl. xix. fig, 3, 4. 
4Aigoc. Belcheri, Wricut, Ibid., pl. xix. fig. 1, 2 (not pl. xv. fig. 7-9). 
Aigoc. Johnstoni, Neum., Unterst. Lias, Abhandl. geol. Reichsans. Wien, VII. pleut fig: 2: 
igoc. torus, Neum., Ibid., pl. iii. fig. 38. 
4igoc. Johnstoni, WAu., Unt. Lias, Mojsis. et Neum., Beitr., IV. pl. xvi. fig. 6-9. 
Localities. — Wiesloch near Heidelberg, Bristol, Cheltenham. 
This form differs from plunorbe in the outline of the whorl, which is much 
narrower, more rotund and gibbous laterally, and in the greater prominence of 
the pilee. 
A specimen in the Museum of Stuttgardt measuring 120 mm., labelled fortilis, 
Nirtingen, has a living chamber still incomplete, though nearly one volution in 
length. Abdomen is slightly more elevated than in typical adult torus and the 
sides more inclined, as is usual in old age of this species. Otherwise the form 
and pilx, especially in the umbilicus, are the same. 
Sutures of adult are similar, as far as seen, to those of Psiloceras, and in old 
age the lobes and saddles decrease in size, becoming simpler in outline. Quen- 
stedt’s specimen, figured in“ Ammoniten des Schwibischen Jura,” Plate I. Fig. 20, 
is 110 mm. in diameter and shows the effects of senility in the compressed whorl. 
His Figure 13 shows the living chamber to have been at least one volution in 
length. The typical forms of this series are found in the Northeastern Alps, but 
the distribution is general, as has been already noted by Neumayr. 
In the collection of the Sorbonne at Paris there is one specimen from Beaure- 
gard precisely similar to that figured by D’Orbigny, except that the whorls are 
much larger and stouter. In the collection at Munich there are specimens from 
Pfonsjoch, Kander in Bresgau, and Lyme Regis, exhibiting the typical form of 
Johnstoni until they reach the diameter of 145 mm. 
Var. Beauregardiense. 
Amm. Beauregardiensis, COLLENOT. 
This form from Beauregard in the collection at Semur is 185 mm. in diameter, 
and has whorls increasing more rapidly in size than in the typical Johnstoni, but 
otherwise does not differ from that species. 
Caloceras tortile, Hyarr. 
Plate I. Fig. 12-14. Summ. Pl. XI. Fig. 14. 
Amm. tortilis, D’Or., Terr. Jurass. Ceph., p. 201, pl. xlix. 
Amm. raricostatus, DunK., Paleontogr., I. ploxin. Ag. 17. 
Aigoceras intermedium, Wriaut, Lias Amm., pl. xv. fig. 5, 6 (not fig. 3, 4). 
Amm. laqueus (pars), Quenst., Amm. Schwab. Jura, p. 19, pl. i. fig. 15, 16 (mot fig. 14, nor p. 18, fig. 4). 
Localities. —Semur, Rinteln, Quedlinburg. 
This species is very generally misinterpreted by German and English paleon- 
tologists. The young have exactly the same broad, gibbous whorl as the young 
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