90 



Data on the morphology of H. arctica larvae in the veliconcha stage are 

 available in works by Odhner (1914), Lebour (1938), Jorgensen (1946); and 

 Rees (1950). Reports on the ecology of reproduction of this species are quite 

 numerous (see above). 



KELLIA JAPONICA PILSBRY 



(Kelliidae) 



Veliger and Veliconcha 



The larvae of Kellia are lecithotrophic and the pelagic period is brief 

 Veligers with a straight hinge at a shell length of over 150 |j.m, emerge from 

 the mantle cavity of females into the plankton. The veliconcha shell is equivalve, 

 round, and flat. The anterior margin is ventrally drawn. Umbones are lacking. 

 The dorsal margin remains almost flat. The larval valves are brittle, transpar- 

 ent, and display weak concentric striation. The larva is yellowish-green. 

 Provincular teeth are absent. The ligament is centered in the dorsal margin (see 

 Figures 39 and 59). The shell of a swimming larva is 360-380 |j.m long. 



Ecology 



Along the southem Sakhalin coast (Aniva Bay, sea of Okhotsk) and in 

 Vostok Bay, larvae of Kellia have been found in the plankton in the second 

 half of summer at water temperatures of about 16— 23°C. 



No data on the morphology and ecology of larvae of this species were 

 found in the literature. 



Figure 59: Hinge of left valve of the veliconcha of Kellia japonica. 



KEENOCARDIUM CALIFORNIENSE (DESHAYES) 

 (Cardiidae) 



Veliconcha 



The description of this species corresponds to that of the entire family. 

 The shell of the swimming larva reaches 280-300 \xm in length, on average 

 (see Figure 51). 



