SUBCLASS II 



DIBRANCHIATA 



687 



Family 2. Ohondrophoridae Fischer. 



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

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

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

 portion or phragmacone. Jura to Recent. 



The members of this family show a further reduction of the guard and phragmacone 

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



.b'iG. ibab. 



Coccoteuthis hastiforinis (Riipp.). 

 Lithographic Stone ; Eichstiidt, 

 Bavaria. 



Fk;. 1334. 



Geuteuthis boUensii Ziuteu. 

 Upper Lias ; Holzmaden, Wiirtem- 

 bt'i-g. Shows ink-bag and cono- 

 thecal striae. V;?- 



Fig. 1335. 



Udoteuthis schuehleri Quenst. 

 Upper Lias ; Holzmaden, Wiir- 



teniberg. '/a (after Quenstedt). 



shells should 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 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 are occasionally found in the Lithographic Stone 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 

 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. L"''i)per Jura of Southern Germany. L. gigas v. Meyer. 



Geoteuthis Mlinst. (Fig. 1334). Proostracum composed of thin alternating horny 



