602 



MOLLUSCA 



SUB-KINGDOM VI 



Family 2. Chondrophoridae. Fischer. 



Proostracum much elongated, thin, composed of conchiolin or of alternating layers of 

 calcareous and horny matter, thickened posteriorly, and without conical alveolar cavity. 

 Jura to Recent. 



Goccoteuthis, Owen (Trachyteuthis, v. Meyer (Fig. 1256). Proostracum elongated- 

 oval, composed of calcareous and horny laminae, rounded posteriorly or with but 

 slightly projecting mucro ; external surface roughly granulated, and marked by lines 

 diverging from the apex. These lines limit the boundaries of two wing-like 

 expansions projecting from the sides of the elongated median portion. Impressions of 

 the body and arms occasionally found in the Lithographic Slates of Bavaria. Upper 

 Jura. 



Leptoteuthis, v. Meyer. Proostracum very large, thin, narrowing posteriorly, and 

 composed of several layers of calcareous and horny layers. Median area ornamented 



FIG. 1256. 



Coccoteuthis hastiformis, Eiipp. 

 sp. Lithographic Slates ; Eich- 

 stadt, Bavaria. 



FIG. 1257. 



Beloteuthis Schvebleri, Quenst. 

 Upper Lias ; Holzmaden, Wiir- 

 teniberg. 1/2 (after Quenstedt). 



FIG. 1258. 



Geoteuthis Bollensis, Zieten. 

 Upper Lias ; Holzmaden, Wiirtem- 

 berg. Shows ink-bag and cono- 

 thecal striae. V- 



with fine undulating transverse striae, convex toward the front, and separated from the 

 lateral areas by longitudinal lines diverging from the apex. Lateral areas marked 

 with oblique inwardly directed lines, and bordered by lateral expansions which are 

 widest posteriorly. Upper Jura of Southern Germany. L. gigas, v. Meyer. 



Geoteuthis, Miinst. (Fig. 1258). Proostracum composed of thin alternating horny 

 and calcareous layers, widest in front, rounded posteriorly. Median area divided into 

 halves by a longitudinal line, and bounded on either side by lateral areas with 

 hyperbolic striae. Ink-bag frequently preserved, the contents transformed into a jet-like 

 substance. It is possible to dissolve the carbonaceous particles so as to prepare a wash 

 resembling India ink. Upper Lias of Germany, France, and England. 



Beloteuthis, Miinst. (Fig. 1257). Proostracum very thin, elongated, feather-shaped, 



