GRAMMOCERAS FALLACIOSUM. 205 



1883. Habpoceeas badians, Wright (non Reinecke). Ibid., vol. xxxvii, pi. Ixxiv, 



figs. 1, 2. 



1884. — — — i5«(/., vol. xxxviii, pi. Ixxxi, figs. 4 — 6. 



1885. — FALLACiosuM, Haug. Beitr. Monogr. Harpoceras ; Neues 



Jahrbuch fiir Mineralogie, &c., 

 Beil.-Baud iii, p. 616. 

 1885. Ammonites eadians, Quenstedt. Amm. Schwiibischen Jura, pi. li, fig. 4 ; 



pi. liv, fig. 56. 

 1885. — — DEPBEssus, Quenstedf. Ibid., pi. Iii, fig. 6. 



1885. — — GiGAS, Qmnstedt. Ibid., pi. li, fig. 3. 



1885. — cf. EADiANS, Quenstedt. Ibid., pi. liii, fig. 13. 



1887. — (? Haepoceeas) Stbtjckmanni, jDewc^jManw. I'auna von Dorn- 



ten ; Abhandl. der geol. Specialkarte von 

 Preusseu und den Thiiriugischen Staaten, 

 Bd. viii, Heft 2, pi. iii, fig. 1. 

 1887. Ammonites (? Habpoceeas) Bingmanni, Denckmann. Ibid., pi. v, fig. 4 ; 



pi. vi, fig. 5 ; pi. X, fig. 17, p. 71. 



Discoidal, compressed, hollow-carinate. Whorls ornamented with ventrally- 

 projected subarcuate or subsigmoidal radii, which are considerably flattened ; and 

 each one being, as it were, badly joined to its predecessor causes an intermediate 

 hair-like rib in the intervening sulcus (p. 201). Ventral area sloping, sometimes 

 acute. Inclusion variable. Umbilicus shallow. Termination subsigmoid, with a 

 ventral projection.^ Suture-line* simple, a prominent and broad superior lateral 

 lobe, a well-defined inferior lateral lobe. 



Since specimens of this species have been previously figured in the volumes of 

 this Society, although under the incorrect name Harpoceras radians (see 

 synonyms, p. 187), I have thought it unnecessary to occupy space with more 

 than a few supplementary figures. It should, however, be noted that in Dr. 

 Wright's Monograph on the Lias Ammonites, the specimens figured on pi. Ixiv 

 are without the test, and the ventral area is depicted as if it possessed a distinct, 

 sharp, prominent, solid carina, the text intimating nothing to the contrary. The 

 species when perfect has a hollow carina, but if the test be absent the hollow 

 carina is removed, and the core exhibits only a very small, blunt, rounded, false 

 carina, which sometimes appears more conspicuous because part of the partition- 

 band, and some of the infilling of the hollow carina, may be attached to it in 

 places. This latter condition is the case in Ch-amm. Muelleri, PI. XXXV, fig. 2 

 (p. 209) ; and it is the restoration of this infilling into the semblance of a keel 

 which has led to the false appearance in the above-mentioned plate. I have 

 commented upon a similar fault in Oppel's drawing of Haugla Eseri (p. 156). 

 The shape of the ventral area without test (in section) may be seen in my Plate 

 XXXIV, fig. 4. The difference which the presence of the hollow carina makes 

 1 Wright, pi. Ixxiv, fig3. 1, 2. 2 Pi. xxxiv, fig. 5 ; pi. a, figs 39, 40. 



