Maitai Series of Netv Zealand. 59 



belonging to the Survey upon which his identification must have 

 been based I see that they are really Strophalosia. The narrow area 

 in both dorsal and ventraL valves as well as the dental sockets in the 

 dorsal valve are clearly apparent, and there is a large and prominent 

 cardinal process. 



The specimens are too imperfect to make any sure specific 

 determination. In one specimen, Fig. 5, the shell is rather wider 

 than long. The dorsal and ventral valves are strongly concavo- 

 convex, and the dorsal valve has a rather foliaceous surface and the 

 spines are short and curved. I have some Strophalosias from the 

 Upper Marine Per mo-Carboniferous of Maria. Island, Tasmania, which 

 rather resemble the New Zealand form. Taking into consideration 

 the concavity of the dorsal valve and other features, the only 

 described Australian form which it resembles in these respects is 

 S. Gerardi, King, an Indian species which Etheridge records from 

 various localities in Queensland and Tasmania. 1 King's figures of 

 this Himalayan form are verv like one of the New Zealand examples, 

 Fig. 5. 



Locality. — Maitai Limestone, Wairoa Gorge. I saw many sections 

 of Strophalosia in the limestone near Martin's Saw-mill. 



Rhynchonella (?puynax) cf. pleurodon, Phill. (PI. V, Figs. 6-8.) 

 Several casts of a small Rhynchonellid were obtained from the 

 decalcified portions of the Maitai Limestone, from which 1 made 

 gutta-percha squeezes. The beak is pointed, rather prominent, and 

 slightly bent over, and has a well-marked triangular area. There 

 are eleven or twelve ribs on the dorsal valve, which commence at the 

 apex ; the middle four or five ribs are straight, but the lateral ones are 

 slightly curved, and the intervening furrows are deep and angular. 

 The mesial ventral sinus and dorsal fold are only very slightly 

 indicated. It is impossible to see anything of the internal structure. 

 This form agrees very closely in outward appearance with the 

 above species, and is comparable with a specimen figured by Davidson 

 (pi. xxiii, fig. 11), but is less alate and has a rather more prominent 

 beak. It also resembles, except for the slight differences mentioned, 

 an Australian Permo-Carboniferous specimen figured by Koninck. 2 



Martinia (Martiniopsis ?) subradiata, G. Sow. (PL V, Fig. 3.) 

 Hector recorded Spirifer glaber from Maitai Limestone, but I did 

 not see the specimen upon which his identification was founded. 

 However, I collected a single ventral valve of a smooth Spirifer which 

 exactly resembles externally the ventral valves of specimens that 

 I obtained from the Upper Marine Permo-Carboniferous of Branxton 

 and Gerringong in New South "Wales. The median sinus is broad 

 and shallow, and is continued to the apex. The rest of the shell is 

 rounded and has a rather foliaceous surface with two or three very 

 faint rounded lateral ribs. The hinge-line is considerably less than 

 the width of the shell. 



1 Jack & Etheridge, Geology and Palceontology of Queensland, 1892, p. 260. 



2 Palceozoic Fossils of New South Wales, p. 170, pi. ix, fig. 4. 



