CEICK : ON AMPHOREOrSIS PAUCICAJIEItATA. 137 



The character of the aperture at once distinguishes this fossil from 

 Gomphoceras, and the form of the specimen shows that it is not 

 a truncated example of Orthoceras. Its affinities are rather with the 

 Poterioceratidfe and Cyrtoceratidse. Though somewhat resembling 

 a truncated form of Poteriocerm, it differs from that genus in several 

 respects: (1) in having the greatest convexity of the body-chamber 

 on the outer instead of the inner curvature ; (2) in the length of the 

 bodj'-- chamber, the last septum in that genus being at about the point 

 of greatest inflation of the shell, whilst, in the present specimen, the 

 greatest inflation is at about the mid-length of the body-chamber ; and 

 (3) in the character of the muscular attachment, this being quite 

 different from the attachment, so far as we have observed it, in 

 undoubted examples of that genus. On the whole, and particularly 

 as regards the character of the muscular attachment, the form appears 

 to belong to the Cyrtoceratidse. It does not, however, seem to be 

 included in any of the members of that family already recognised. 

 It comes nearest the genus Cyrtoceras, especially that section for which 

 Foord ' has adopted Hyatt's name Meloceras as a subgeneric title, but 

 differs from that genus in the general form and relatively large size 

 of the body-chamber. I feel compelled, therefore, though reluctantly, 

 to regard it as a new genus. On account of its form I propose for 

 this genus the name Amphoreop&is^ and in allusion to the fewness 

 of the cameras (or so-called air-chambers) suggest, as the trivial name, 

 paucicamerata. 



EXPLANATION OF PLATE VIII. 



Type-specimen of Amphoreopsis paucicamerata, G. C. Crick, from the Poolvash 

 Limestone (Carboniferous), Poolvash, Isle of Man. Fig. 1, dorsal aspect; 

 Fig. 2, left lateral aspect ; Fig. 3, ventral aspect ; Fig. 4, right lateral 

 aspect. About three-fourths of tbe natural size. «, portion of the peristome ; 

 d, constriction on the anterior part of the internal cast of the body-chamber ; 

 g, groove on posteiior surface of the internal cast of the penultimate chamber ; 

 r, ' shoulder ' indicating place of detachment of earlier chambers ; s, last 

 septum ; «', ridge indicatmg edge of penultimate septum ; si, siphuncle ; 

 sin, boundary of impression of muscle-scar. 



' Carboniferous Cephalopoda of Ireland (Mou. Pal. Soc), pt. 2, 1898, pp. 33 



et seqq. 

 ^ afi(popevs, a wine-jar, and o^'is, aspect. 



