350 SAXICAVIDiE. 



Genus GLYCIMERIS, Klein. 



Siphons large, united as far as their extremities, and in- 

 vested with a thick, wrinkled epidermis. 



Shell transversely ohlong, gaping at the sides, valves with 

 the surface wrinkled and grooved transversely, and covered 

 with an epidermis. Hinge composed of a single strong tooth 

 in each valve, which is received into a corresponding pit of 

 the opposite valve ; ligament conspicuous, external. Pallial 

 impression continuous, with a deep posterior sinus. 



Ex. G. Natalensis, Woodward, pi. 93, fig. 2. Shell, 

 G. rngosa, Bosc. fig. 2, a, 2, b. 



The Glycimeris of Klein has heen kept as a genus dis- 

 tinct from Panop&a on account of the siphons of the animal 

 being united as far as their ends, while in Pa/wpaa they are 

 separate at their extremities ; the gills also are short as in 

 My a. The shells, however, of the two forms are very 

 similar, the principal difference being in the character of 

 the pallial impression, which in Glycimeris is continuous, 

 but in Panopa>,a broken up into a few scattered spots as in 

 the genus Saxicava. Glycimeris is founded on the My a 

 glycimeris of Bom, which is the same as the Panopaia 

 Aldrovatidi of Menard, and the Mya rugosa of Bosc. 



Species of Glycimeris. 



abbreviata, Valenc. Natalensis, Woodiv. 



antarctica, Gould. rugosa, Bosc. 



australis, Soiv. Solandri, Gray. 



generosa, Gould. Zelandica, Quoy and Gahn. 

 Japouica, A. Adams. 



