The marine Carboniferous of Nortli-east Greenl. and its Brachiopod Fauna. 585 



having been filled with calcite which could be worked away. In 

 the same boulder there is visible on the surface the sections, filled 

 with calcite, of two Productiis shells which, with tolerable certainty, 

 may be ascribed to this species. The figure shows the cast of the 

 sculpture of the dorsal valve, a fragment of the latter and finally, 

 a part of the calcareous mass that had filled the visceral room. 



Our specimen agrees very well with Wiman's figures, both as 

 regards sculpture and form; a wax impression of the ventral valve 

 shows the agreement still better. Our specimen has not reached 

 such an age that a geniculation of the ventral valve towards the 

 front line can be noticed, such as is pictured by Wiman from older 

 specimens. 



This species occurs numerously in Spitzbergen in the white, 

 sandy Spirifer limestone on Lovén's Mountain, and some likeness 

 can be noted between the rock in лvhich the specimen from North- 

 east Greenland occurs, and the Spirifer limestone of Lovén's Mountain. 



N:o 24. Productus punctatus Martin. 



PI. XXIX, Fig. 5. 



For synonyms see Tschernyschew, 1902, pp. 296, 297 ; Girty 

 1903, p. 368, Fliegel, p. 101 and Thomas p. 303. 



Of this species I have only the specimen figured, a dorsal valve, 

 found on Amdrup's Land at the Eastern river in light-red limestone 

 {N.0 160). In dimensions it attains the figures given for large spe- 

 cimens, and, on the whole, it agrees with, e. g., Davidson's figuring, 

 PI. 44, Figs. 9 and 11. As regards the sculpture of the valve, no 

 difference can be observed between our specimen and Davidson's 

 figure 10 b, PI. 44, and the description that Vaughan (1906, p. 307) 

 gives of the shell-sculpture of this species as compared with that of 

 Pr. pustulosus Phill. and Pr. fimbriatus Sow., is perfectly applicable to 

 our specimen. Vaughan says: Tn the type of Pr. punctatus the 

 spine-bases are extremely numerous, small, and closely packed, three 

 to four concentric rows ornamenting each concentric band (the spines 

 which compose the uppermost row on each band are always longer 

 than those of the lower rows)". On one piece of the surface of the 

 valve there are visible spines still remaining, and spines are spread 

 pretty abundantly in the rock. 



This species is widely distributed, both horizontally and verti- 

 cally. It seems to have its chief niveau in the Lower Carboniferous, 

 but Holtedahl (1911, p. 35) slates that it occurs abundantly in the 

 mosquensis limestone at King's Bay, in Spitzbergen, while Tscherny- 

 schew mentions it both from the Omphalotrochus limestone in Ti- 

 man, and the Schwagerina horizon in the Urals. 



