FROM NORTHWESTERN EUROPE 93 
Septaliphoria (?) hudlestoni (Rollier) 
(Pl. 9, figs. 1-4) 
1878 Rhynchonella pinguis Roemer; Davidson: 193-94, pl. 16, fig. 7. 
1878 Rhynchonella pinguis var. pectunculoides Etallon; Davidson: 194-95, pl. 16, figs. 8-12. 
1917 Rhynchonella Hudlestoni Rollier: 172. 
1933 Rhynchonella covallina Leymerie; Arkell: 435. 
1947 Rhynchonella pinguis Roemer; Arkell: 87. 
EMENDED DIAGNOSIS. Medium to large Septaliphoria-like form ; 15-20 coarse, 
subangular ribs ; uniplication in anterior commissure symmetrically or asymmetric- 
ally developed. 
STRATIGRAPHICAL RANGE. Kimmeridgian—cymodoce zone. 
TYPE SPECIMEN. Lectotype, here selected, fig. 10, plate 26 in Davidson (1878) ; 
collected from Abbotsbury Ironstone, Dorset. B.M. B. 27333. 
MATERIAL. 34 specimens in the collection of the B.M.(N.H.) from Abbotsbury, 
Dorset, B. 26853-54, B. 26856, B. 26858, B. 26859. 8 specimens in author’s collec- 
tion, (from the same locality). 
DESCRIPTION. External characters. In general the specimens are very poorly 
preserved. The species appears to be very variable ; many of the specimens show 
asymmetrical development of the uniplication in the anterior commissure, although 
never the “ bilobed’”’ type of asymmetry found in Torqurhynchia. The globose 
specimens tend to show asymmetry more than the flatter ones which are often weakly 
trilobate in appearance ; the latter forms also have a higher and more pronounced 
beak. 
The beak ridges are very weak and the interarea is narrow and incurved. It would 
appear that the pedicle opening is small and circular but details of both this and the 
deltidial plates have not been satisfactorily observed. Radial ornament consists of 
about 15-20 coarse subangular ribs, while the only concentric ornament observed has 
been a few very weak growth lamellae on exceptionally well preserved specimens. 
DIMENSIONS OF FIGURED SPECIMENS. 
length thickness width 
3:00 cm 2°60 cm 3°24 cm 
2°73 cm 1-98 cm 2-78 cm 
2°54 cm I-70 cm 3°10 cm 
Internal characters. An attempt was made to section an apparently well pre- 
served specimen. Unfortunately, the external appearance was deceptive and 
virtually nothing could be seen of the internal structures except that a median 
septum and a possible septalium were present in the brachial valve. Mr. E. F. 
Owen (personal communication 1966) stated that he has attempted to section 
several specimens and in all cases it was impossible to determine the internal 
structure. 
DISTRIBUTION. The only known occurrence of the species is in the Abbotsbury 
Ironstone of Dorset. 
