SUBOLASS II 



DIBRANCHIATA 



687 



Family 2. Ohondrophoridae Fischer. 



Internal shell in the form of a much elongated thin plate or jproostracum, divided 

 lenrjthwise into three areas, composed of conchiolin or of alternating layers of calcareous 

 and horny matter, thickened posteriorly, and ivith very little trace of any chambered 

 portion or phragmacone. Jura to Recent. 



The ineinbers of this faiuily show a further reduction of the guard and phragmacone 

 than occurs in the stage represented by Belemnotenthis, and their horny, non-septate 



Coccoteuthis Jiastiformis (Rüpp.). 

 Lithographie Stone ; Eichstädt, 

 Bavaria. 



Fi(i. 1334. 



Geoteuthis bollensit, Zieten. 

 Upper Lias ; Holzmaden, Wiirtem- 

 berg. Shows ink-bag and cono- 

 thecal Striae. 1/3. 



Fig. 1335. 



Beloteuthis schuebleri Qnenst. 

 Upper Lias ; Holzmaden, Wür- 

 teniberg. 1/2 (after Quenstedt). 



Shells shoiüd be compared with the pen of the common squid or calamary, Loligo 

 vulgaris Lam. 



Coccoteuthis Owen {Trachyteuthis v. Meyer) (Fig. 1333). Proostracum elongated- 

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

 slightly prqjecting 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 j^ortion. Impressions of 

 the body and arms are occasionally found in the Lithographie Stone of Bavaria. 

 Upper Jura. 



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

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

 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 Münst. (Fig. 1334). Proostracum composed of thin alternating horny 



