I90I S. S. BUCKMAN — BRACHIOPODA 257 



VI. Non-plicate Homceomorphs 



II. TEREBRATULA MICROTRYPA, S. Btickman, sp. n. 



PI. XIII., figs. 3a, b, c. 



Description : — Valves convex, the pedicle valve more so than the 

 other; valves tapering to the margin. Shell in outline sub-circular. 

 Beak small, short, sub-tumid, slightly overhanging, not distant from 

 umbo. Beak ridges defined, sub-acute ; foramen small. 



No^e. — A ground-down specimen shows a short loop. 



Distinction : — From Terebr. ampla and T. Uptoni, it 

 is a smaller shell. From young T. ampla, it has more 

 gibbous valves, it is not so broad posteriorly, it is more 

 inflated around the beak, which is more curved and has 

 more definite beak ridges, and the foramen is smaller. 

 From immature T. Uptoni, the more gibbous valves, 

 transverse shape, and the beak characters, with beak closer 

 to the umbo, separate it. 



Locality and Stratum : — Somerset : Horethorne Down, 

 near Gorton Denham, in a bluish marly clay with Rhyn- 

 chonella Forbesi, etc. 



Note : — I have two specimens sent from Dundry by Mr 

 Marshall, which are very like this species ; but as the beak 

 characters are not well preserved, there may be doubt as 

 to specific identity. 



12. ZEILLERIA CIRCULARIS, S. Buckman, sp. n. 



PI. XIII., figs. 9a, b, c. 



Descriptioti : — Valves about equally convex, tapering rather to margin, 

 in outline nearly circular. Umbo prominent, tumid. Beak short, 

 erect, truncate. Beak ridges distinct, sub-acute ; foramen not large. 



Comparison : — Homceomorphs are Terebratula ampla, 

 J. Buckman, and Ps. Leesi (S. Buckman) especially ; 

 T. microtrypa to a certain extent ; and Terebr. lentiformis^ 

 Upton, in less degree. 



