ALARIA. 139 



species to the section of didactyls. It is quite contrary to the original diagnosis 

 of Lycett. Whether this really is an anterior digitation, or merely an accident 

 in the development of the fossil, is a question awaiting further evidence. 



Relations and Distribution. — The excessively rugose and spinous character of 

 this shell, and the comparatively depressed spire, clearly separate this from all 

 other Alarise previously described in this Memoir. Hence there seems to be little 

 danger of its being confounded with any one of them. But since a doubt yet 

 remains as to whether the species is didactyl or monodactyl, and having regard 

 also to the apparent scarcity of specimens, Alaria spinigera cannot be regarded 

 as fully diagnosed at present. 



Al. spinigera, Lycett, is quoted in Witchell's ' Geology of Stroud,' from the 

 Oolite-Marl. 



58. Alaiua solida, Lycett, 1853. Plate IV, fig. 5. 



1853. A.laeia solida, Lye. Proc. Cotteswold Nat. Field Club, vol. i, p. ?80. 



Description by Author. — " Spire turrited ; whorls few, angulated by a circle of 

 elevated, longitudinal, spinous ribs crossed by lines ; body- whorl with a single 

 carina, beneath which are several encircling grooves ; wing simple, small, 

 proceeding from the carina, caudal extremity short." 



The specimen from which, apparently, the above description was taken, is in 

 the Lycett collection at Jermyn Street, and has the word " solida " still legible 

 upon the reverse. The spiral angle is about 38°. Certain variciform swellings 

 may be traced across the whorls, presenting a feature not often observed, but the 

 specimen is too imperfectly preserved for further description. 



Relations and Distribution. — Though the character of the spire is somewhat 

 similar to that of the last-named species, the ornamentation is less spiny, and 

 what appear to be the variciform lines or swellings seem still further to 

 distinguish it; the spiral angle, also, is considerably less. On the other hand, the 

 short, upturned digitation greatly resembles that which appears to be the posterior 

 digitation of Al. spinigera. The fossil also reminds us somewhat of the form of 

 Alaria (Diartema) hamulus of the Great Oolite and appears to have been derived 

 from the Inferior Oolite of the Cotteswolds. 



Alaria solida is not quoted in Witchell's ' Geology of Stroud.' 



