n6 SHELVE DISTRICT 



pedicle valve (BB 35340a, b) from the Meadowtown Beds exposed in the lane to 

 Waitchley 140 yds north of Meadowtown Chapel (Grid Ref. SJ 311014). These 

 meagre fragments indicate that the valve was about 4-0 mm long, 5-5 mm wide and 

 1 -5 mm deep with a high apsacline interarea, slightly acute cardinal angles and a 

 faint antero-medial sulcus. Radial ornamentation consisted of about 20 rounded 

 costae and a few costellae arising by branching with 3 ribs per mm at the antero- 

 lateral margin. The ribs and interspaces were crossed by strong, outwardly de- 

 flected lamellae. This concentric ornamentation is regularly arranged with a 

 density of 4 lamellae per mm at the valve margin and breaks the continuity of the 

 ribs. The valve interior was dominated by a spondylium supported by a median 

 septum extending forward for 1-5 mm. 



Consideration of the valve profile and outline, ornamentation, and the nature of the 

 spondylial support, suggests that the specimen is best assigned to Kullervo. Indeed, 

 sufficient radial ornamentation is preserved to prompt comparison with one of the 

 earliest recorded species, K. panderi (Opik 1934 : 164) from the C 2 horizon of 

 Estonia, because there is no strong differentiation between the postero-lateral and 

 medial sectors of radial ornamentation as in later species. However, until more 

 material is obtained to assess the validity of this comparison, only a generic identi- 

 fication is appropriate. 



Suborder TRIPLESIIDINA Moore 1952 



Superfamily TRIPLESIACEA Schuchert 1913 



Family TRIPLESIIDAE Schuchert 1913 



TRIPLESIA Hall 1859 



Triplesia sp. 



(PI. 19, fig. 16) 



An incomplete internal mould (BB 35408), with fragments of the shell adhering, 

 of the genus Triplesia have been recovered from the Whittery Shales exposed in the 

 stream at the north end of Spring Coppice, 865 yds south-east of Hockleton Bridge 

 (Grid Ref. SO 279997). The mould is that of a pedicle valve which was 12-5 mm 

 long, 10 mm wide and 2-5 mm deep laterally. Its outline was subquadrate with 

 rounded obtuse cardinal angles and it was indented medially by a strong flat- 

 bottomed sulcus, about half as wide as the maximum width of the valve, which 

 was sharply bent into a right angle to project dorsally as a tongue about one- 

 third as long as the ventral length of the valve. The apsacline interarea, which 

 was curved, bore a medially folded pseudodeltidium, and the external surface bore 

 only fine overlapping lamellae numbering about 14 per mm anteriorly. Internally 

 the dental plates were acutely divergent, extending forward for about one-fifth the 

 length of the valve, while the diductor scars were lightly impressed for over half the 

 length of the valve on either side of a low median ridge. 



The Whittery Triplesia with its flat-bottomed sulcus and sharply bent, dorsally 

 projecting tongue is immediately distinguishable from penecontemporaneous 



