DIPLODON 1293 



Var. acutiis Suter. 



'■Disting"uished from the species by the very distinctly ros- 

 trate posterior end. the nearly total absence of radial sculpture, 

 and by being more compressed. ( jnly young shells show traces 

 of radially arranged nodules near the beaks. The basal mar- 

 gin is generally more straight than in typical mencicsi. The 

 beaks are much corroded in all the specimens I have. The shell 

 is rather thin, yellowish-brown, with strong, concentric sculp- 

 ture, approaching D. nigata Hutton. The interior is nacreous- 

 olive, the hinge not different from that of the species. 



Length 70, height 40, diam. t6 mm." (Suter). 



Type locality, Lake Omapere, New Zealand. 

 Diplodon men.ziesi subsp. acuta Sutkr, Pr. Mai. Soc. London, 



VU, 1907, p. 239, pi. XXII, figs. II, 12. 



"The outline of this subspecies is very nearly that of D. 

 depauhcrata tJutton, but the hinge is very different ; it also 

 has almost exactly the outline of Anodonta complanata Zeig- 

 ler of Europe." 



Var. litcasi Suter. 



"Shell oblong-ovate, very much compressed, thin and frag- 

 ile, inequilateral, beaks low, eroded ; surface with close, strong- 

 ly pronounced rest-marks and between them a few lines of 

 growth, all close together and foliated at the anterior end. In 

 the adult specimen the middle part has distinct, radiate, nod- 

 ulous sculpture, partly \'-shaped, but no such ornamentation 

 is to be found on the young specimens. The straight dorsal 

 margin is subparallel to the ventral anargin, which is slightly 

 sinuate; the anterior margin is angularly rounded, the poste- 

 rior obliquely truncated and slightly produced. Nearly the 

 whole shell is covered wdth a thin ferrugineous coating; the 

 epidermis is olive-green, waxy. The ligament is small, not 

 much raised. In the right valve the two pseudocardinals are 

 compressed, small ; the upper anterior tooth is a small, smooth 

 lamella, the lower tooth is more elevated, conoidal and strong- 

 ly crenate ; the lateral tooth is almost straight, thin and rugose 

 at its posterior portion. In the left valve there is a rather long, 

 compressed, lower, anterior, rugose pseudocardinal, the upper 



