SECOND, OR SCHLOTHEIMIAN BRANCH. 129 



FjRST SUBSERIES. 



Schlotheimia catenata, Wahner. 



Summ. PI. XI. Fig. 3. 



Amm. catenatus, Sow., De la Beohe, Traite de Geol., p. 407, fig. 67. 



Aram, catenatus, D'Okb., Terr. Jurass. Ceph., p. 301, pi. xciv. 



JEgoc. catenatus, Weight, Lias Amm., p. 320, pi. xix. fig. 5-7 ; pi. xvii. fig. 3-6. 



Schlot. catenata, Wah., Unt. Lias, Mojsis. et Neum., Beitr., IV., 1886, p. 196. 



jEgoc. subangulare, Wah., Unt. Lias, Mojsis. et Neum., Beitr., IV., 1886, p. 162. 



Amm. angulatus thalassicus, Qdenst., Amm. Schwab. Jura, pi. ii. fig. 9 (not fig. 4, 5). 



Amm. angulatus psilonotus, Quenst., Ibid., pi. ii. fig. 10, 11. 



Amm. angulatus hircinus, Quenst., Ibid., pi. ii. fig. 12. 



Amm. angulatus oblongus, Quenst., Ibid., pi. ii. fig. 6. 



JEgoc. angulatus, Neum., Unterst. Lias, Abhandl. geol. Reichsans., VII. p. 33, pi. ii. fig. 5. 



JEgoc. subangulare, Neum., Ibid., p. 33. 



Localities. — Chevigny near Semur, Balingen, Diebrook near Ravensburg, Miihlhausen, Coppenbriigge 

 in Westphalia, Hildesheim, Markoldendorf. 



In the collection of the Museum of Stuttgardt from the Planorbis bed there 

 is a specimen of this species, which is more discoidal than /Schlot. angitlata, and 

 more like Wsehneroceras in its aspect than any other members of this series, and 

 the same facts are observable in Quenstedt's collection. In the collection at 

 Semur there are three specimens from the Planorbis bed correctly named catenatus. 

 They are not large, and one specimen at the diameter of 52 mm. shows signs of 

 old age in its obsolescing pilae and smooth abdomen. We have also examined 

 D'Orbigny's types and confirmed these comparisons. Neumayr compares his 

 specimen from the Planorbis bed of Pfonsjoch with the North German species of 

 angnlahis, which is a true catenatus, and in Professor Emerson's collection from 

 Markoldendorf, now at Amherst, Mass., all specimens of this species agree very 

 closely with catenatus as figured by Quenstedt. The pilae cross the abdomen with 

 a forward bend, but in one precisely the peculiarities of Quenstedt's Fig. 12 

 are exhibited, the pila? being straight as they cross the abdomen. Amm. ang. 

 oblongus, Quenst., may be a large variety ; the whorl as figured resembles that of 

 catenata. 



Schlotheimia striatissima, HrATT. 



Amm. angulatus striatissimus, Quenst., Amm. Schwab. Jura, pi. iii. fig. 2. 

 Amm. angulatus striatus, Quenst., Ibid., pi. iii. fig. 3-5. 



Locality. — Semur. 



Two specimens of this species in the Museum of Comparative Zoology and 

 Quenstedt's descriptions and figures show that it is a discoidal shell like catenata, 

 but the abdomen is narrower, the whorl more compressed, and the pila3 more 

 numerous and finer than in that species. They remind one in this respect of the 

 second subseries, but unfortunately there are no transitional modifications by 

 which to follow out the connection, if it existed, with these dwarfed forms of the 

 Oxynotus bed. The mould of the young specimen supposed by Quenstedt to 



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