part 3] Jurassic rocks of new Zealand. 279 



and T. V-costata Morris & Lycett of the ' Lower Oolite.' Gottsche 

 records the similarity of T. lycetti to T. V-costata. 



Hector's ' Trigonia navis var.' l is apparently intended to 

 represent the shell now described. 



Astarte. 



Dr. Karl Holdhaus recorded and described four species of 

 Astarte from the Spiti Shales. 3 These are A. hermanni Oppel, 

 A. soioerbyana Holdhaus, A. scytalis Holdhaus, and A. spitiensis 

 Stoliczka. The first two are very similar one to the other, and 

 the last is said to be distinguished from them by its shell being 

 higher and having a more rounded outline. 



Holdhaus remarks that these Spiti species of Astarte are not 

 clearly related to any extra-Indian forms, and, owing to his lack 

 of opportunity of examining the specimens, it is uncertain whether 

 or not A. hermanni and A. sowerbyana may be identical with 

 A. unilateralis Sowerby and A. minor Sowerby from Kach. By 

 comparison with Sowerby's illustrations, however, it is suggested 

 that this may be so. 



Several Astartes that I collected at Totara Point undoubtedly 

 belong to this group ; but, owing to the fact that, except in two 

 or three instances, the shell is broken round the edges, an abso- 

 lutely certain specific attribution is not advisable. 



Astarte spitiensis Stoliczka. (PL XIII, figs. 1 a & lb.) 



1866. Mem. Geol. Surv. India, vol. v, p. 91 & pi. ix, fig. 9. 



1913. K. Holdhaus, ' Fauna of the Spiti Shales (Lamellibranchiata & Gasteropoda) ' 

 Pal. Ind. sar. 15, vol. iv, pt. ii, fasc. 4, p. 444 & pi. c, figs. 4-8. 



Description. — Beaks anteriorly situated, small, projecting 

 considerably above the hinge-line. The latter is very slightly 

 curved, and occupies about two-thirds of the length of the shell. 

 The upper posterior margin is bluntly angular, the posterior 

 margin gently rounded, the lower margin well rounded, the 

 anterior margin rather produced and rounded. In front of and 

 below the beak is a sunken heart-shaped lunule, forming a rounded 

 excavation that extends over less than a quarter of the height of 

 the shell. The surface of the shell near the umbones is rather 

 flattened, the flattening extending nearly to the level of the lower 

 part of the lunule. The flattened part is decorated with more or less 

 ecpiidistant, prominent, and rather foliaceous growth-lines. Below 

 this the surface is gently rounded, and has a very faint angulation 

 extending from behind the beak to the lower posterior margin. 

 It is decorated with closely but irregularly set growth-lines which 

 vary in strength. On the posterior part between the angula- 

 tion and the hinge-line they are very closely set and rather 



1 ' Catal. Ind. & Col. Exhib.' 1886, p. 69, fig. 3. 



2 ' Fauna of the Spiti Shales (Lamellibranchiata & Gasteropoda) ' Pal. 

 Ind. ser. 15, vol. iv, pt. ii, fasc. 4 (1913) p. 440 & pis. xcix-c. 



Q. J. G. S. No. 315. x 



