THIRD, OE VEEMICEEAN BEANCH. 



147 



Fig. 23, 24. Views from the side and abdomen of Cal. aplanatum. 



Bean, and were said to have been found in the Lower Lias. Their young, seen 

 from the side and only in the umbilicus, have the peculiar pike and general 

 aspect of raricoslalus, with similar rotund sides and fine closely set pike. 



Cal. (Ariel.) prcespiratissimum, Wah., 1 has distinctly caloceran sutures and pilas 

 without geniculse. It develops a keel at an early stage, and has a subquadragonal 

 whorl in the adult with slight channels. It is a close morphological equivalent 

 of the Vermiceran-like variety of Cal. laqueum of Central Europe, if not identical 

 with it, and is certainly, as stated by Warmer, transitional to Ver. spiralissimiim. 



Warmer's figures prove that Cal. p>roaries is a form with late development of a 

 keel, the exact equivalent of Cal. Nodotianum in the Central European province. 

 Wahner's full series of young and adults, 2 and Neumayr's senile specimen figured 

 in Unterster Lias, 3 show that the young of Cal. proaries (Plate XXX. Fig. 7) resem- 

 ble very closely the adult stages of Psil. sitblaqueum, Wah. (Plate XXX. Fig. 4), 

 Cal. Johnsloni (Plate XVI.), and Cal. {Psil.) orthoptychum, Wah. (Plate XXVII. 

 Fig. 2), and the unnamed form figured on Plate XXVII. Fig. 3. Cal. (Psil.) 

 gonioplychum, Wah., 4 has the same compressed whorls as in the more advanced 

 stages of proaries, and appears to be intermediate between that species and Cal. 

 cycloides. The sutures agree with those of proaries. We venture to differ from 

 Warmer, who associates this species more closely with Cal. Sebanum of the Pla- 

 norbis bed. The apparently intermediate aspect and characteristics seem to 

 have been inherited at an earlier stage than in proaries, but not quite so early 

 as in cycloides, if one can use figures for arriving at such conclusions. Cal. (Ariel.) 



1 Mojsis. et Neum., Beitr., V. pi. xxi. 



3 Abhandl. geol. Reichsans., VII. pi. xxviii. 



2 Ibid., IV. pi. xxviii.-xxx. 



4 Mojsis. et Neum., Beitr., IV. pi. xxvii. 



