180 GASTEROPODA OF THE INFERIOR OOLITE. 



are distinguished by large oval granulations, drawn out spirally, but arranged so as 

 to form the axial costse of the spire. In the body-whorl the oval granulations are 

 sometimes lost. Body-whorl much constricted anteriorly, and not unfrequently 

 showing a tendency to detach itself. Aperture small, thickened, and orbicular. 



Relations and Distribution. — This species was originally described from a 

 specimen obtained from the Millepore Rock of the Yorkshire coast, which differs 

 in some details from "Weldon specimens. It is more slender than Ex. strangulata, 

 besides differing very much in ornamentation. The large oval granulations and 

 general coarseness of the spiral lines completely distinguish this species from Ex. 

 pulchra and Ex. formosa. 



110. Exelissa Nokmanniana, UOrb., 1850. Plate XI, fig. 9. 



1850. Cerithium Normahnianum, I? Orb. Prod., i, p. 271. 



Bibliography, fyc. — D'Orbigny describes his species as near to C. contortum, 

 but shorter and provided with seven longitudinal rows of costae. It occurs at 

 Bayeux. By the kindness of Prof. Eugene Deslongchamps I possess a specimen 

 from the " Oolite ferrugineuse," thus identified. It is barely 12 mm. m length, 

 and is pupaeform, so that its resemblance to C. contortum is very slight indeed. It 

 has seven longitudinal rows of costse, as stated by D'Orbigny. Whether it should 

 be referred to Exelissa or to Crijptaulax is not quite clear. The small size and 

 pupoid shape are in favour of the former view, whilst the ornaments are more 

 those of Cryptaulax. N"o perfect aperture has been seen by me. 



Description. — Length about 10 mm., width two-fifths of the length. Shell 

 pupgeform. Number of whorls about eight, polygonal, and well separated by the 

 suture, the last whorl narrowing towards the base. Ornaments rugose ; regarded 

 longitudinally, i. e. in the direction of the axis, there are eight rows of costge, the 

 spirals in each whorl being three in number, and grossly tuberculated for so small 

 a shell, especially as regards the first and third spirals. Columella short and 

 encrusted by the peristome, which is subcircular and situated in the base of the 

 shell. Other indications wanting. 



Relations and Distribution.- — In size, shape, and details of ornamentation, 

 English specimens agree fairly well with those from Bayeux, the chief difference 

 being that there are eight rows of costee instead of seven. 



It may be that this rugose little species serves to form a connecting link 

 between Exelissa and Cryptaulax. Before deciding we await better specimens ; 

 both Exelissa and Cryptaulax are very tender in the mouth. 



Occurs at Stoford, Burton Bradstock, and Grove — in the Parhinsoni-zone. 



