:218 DE. c. T. TRECHMANK^ oif [voL Ixxiii, 



Valves somewhat flattened. The beak is prominent, but receding ; 

 the foramen is large and rather diagonally situated, having en- 

 croached on the beak through absorption or wear. The delthyrium 

 seems to have been partly covered by the dorsal beak. The dorsal 

 valve bears near its anterior margin a very faint, broad, mesial 

 fold and lateral sulci. Owing to. the extremely-slight plication, 

 the junction of the valves is nearly straight. The growth-lines are 

 well marked on the cast. 



Dental plates are well developed in the ventral beak. In the 

 dorsal valve a strong median septum extends for more than a 

 third of the length of the shell, and supports a prominent shield- 

 like hinge-plate. 



Length 1=46 mm.; width = 33 mm. ; thickness = 16 mm. 



Locality and horizon, — Kaihiku Beds, Caroline Cutting, 

 Hokonui Hills. Two casts were collected, one of them crushed. 



Remarks. — This form differs from the numerous small Die- 

 lasmas in the Kaihiku Beds, in its very much larger size and more 

 prominent beak. I could not ascertain either the structure of the 

 crura, or the nature of the shell. Although it is only a cast, its 

 distinctive characters justify the attribution to it of a specific 



CCENOTHYEIS sp. (PI. XXIII, fig. 7.) 



Shell subpentagonal in outline, rather inflated ; the beak tapering 

 slowly, fairly prominent, and bent over so that the area and part 

 of the foramen are hidden by the dorsal beak. The dorsal valve 

 has a broad and high median fold, bounded on each side by a 

 broad and shallow sulcus, which merges into the rounded surface of 

 the shell. Near the anterior margin the median fold has a faint 

 sulcus on it. 



The internal cast shows that dental plates are well developed, but 

 apparently in part calloused. There is a slight median septum in 

 the dorsal valve, but nothing of the loops could be seen. 



Length =30 mm. ; width = 28 mm. ; thickness = 17 mm. 



Locality and horizon. — A single specimen in my collection 

 occurred in the JPseudomonofis-riclimondiana Beds at Kichmond, 

 near Nelson. Noric. A gutta-percha squeeze of the beak and 

 dorsal valve was obtained from the mould. 



Remarks. — This large plicated Terebratulid is the only fossil 

 that I ever saw^ associated with Psendomonotis ricJimondiana, and 

 is the only deeply-23licated Terebratulid that I obtained in the New 

 Zealand Trias. 



' TeREBRATULA ' PACHTDENTATA, Sp. nOV. (PL XXIII, fig. 6.) 



Shell oval and gently rounded in oufcline ; the valves are some- 

 Avhat flattened and not inflated, and show no plication. The beak 

 projects but very slightly above the hinge-area, and the foramen 

 is very small. The growth-lines are fairly well marked. The shell 

 is remarkably thickened in the umbonal region of the ventral valve. 



