124 



PEOCEEDTNGS OF THE MALACOLOGICAL SOCIETY. 



We are much indebted to our friend, Mr. F. A. Bather, for the 

 suggestion that the sole specimen upon whicli Edwards founded his 

 genus Uelemnnsis might possibly be a rolled Spindirostra. After 

 ha^■ing carefully compared the specimen with the figures of the latter 

 genus published by its author, M. D'Orbigny, we are enabled to 

 confirm that suggestion, in spite of the fact that at first sight 

 there appears to be but little to support it. Edwards described his 

 Belernnosis as consisting of "an elongated, semi-conical sheath, the 

 apex of which expands into a short semi-cylindrical umbo pierced on 

 the ventral surface, and inflected towards the ventral aspect." The 

 principal distinguisliing character of the genus, he remarked, was the 

 large aperture "which forms a communication between the alveolar 

 chambers and the sac in which the shell was lodged." Another 

 important point was the absence of the elongated rostrum so 

 characteristic of Belosepia and Beloptern. "We give a figure (^) 

 of Belernnosis in illustration of the diagnosis drawn up by Edwards. 



Sjnrtilirostra atiomala. 



A = Ventral aspect ; enlarged nearly 4 times. 

 B = Ideal sectional restoration. 



The presence of the ventral aperture, a character not possessed 

 by any other genus of Cephalopoda recent or fossil, should rest on 

 undisputed evidence, it seems to us, before it can be recognised as 

 a true moi-phological feature ; and, there being only one specimen 

 known, this is entirely uncorroborated. Moreover, when that specimen 

 is carefully examined, it is seen to be exceedingly smooth and rounded 

 ofP at the edges ; it does not possess the punctated character so 

 common in its allies, Belosepia and Beloptera, whilst the margin of the 

 aperture is fractured. From these and other considerations suggested 

 by its general appearance we have no doubt that the specimen has 

 been considerably rolled, and that the so-called ventral aperture is 

 in reality only the initial chambers of the shell brought to light 



