﻿MYTILIMERIA.— Plate I. 



The rock-dwelling Mttilimeria. Shell large, ven- 

 tricose, oblong, covered with a strong, horny 

 epdermis, gaping at the ventral and terminal 

 margins ; anterior side short, narrow ; posterior 

 side elongated, ventricose, truncated at the end ; 

 right valve rather flat ; left valve deeply ventri- 

 cose ; dorsal margin depressed, curved ; hinge 

 plate large, thick, convex outside. 



Baird {Lyonsia). Boundary Commission Report. 



Hab. Vancouver's Island. 



It has been found difficult to fix the generic status of 



this fine shell, which differs greatly in form and habit 



from the typical Lyonsia. 



Species 5. (Mus. Brit.) 



Mttilimeria navicula. Myt. testd oblongd, teniii, 

 pallida, injlatd ; umhonihus tumidis, fere tenninali- 

 bus ; latere antico hrevissimo, perpendiculariter 

 truncate; margine ventrali antice sinuato, hianti, 

 postice inflato ; latere postico ohlongo, oblique 

 angulato, ad terminwii truncato ; margine dorsali 

 depresso, rectitlsndo ; valvd dextrd profundd. 



The boat Mytilimeria. Shell oblong, thin, pale, 

 inflated; umboes tumid, almost terminal; anterior 

 side very short, perpendicularly truncated ; ven- 

 tral margin anteriorly sinuated, gaping, posteriorly 

 inflated ; posterior side oblong, obliquely angular, 

 truncated at the end ; dorsal margin depressed, 

 rather straight ; left valve deep. 



Adams and Reeve {Lyonsia). Proc. Zool. Soc, 1836, 

 p. 70. 



Hah. Iquiqui, Peru. 



Species 6. (Mus. Brit.) 



Mttilimeria picta. Myt. testd subrhomboided, solidd, 

 lineis fuscis divaricaiis picta, ad marginem ventra- 

 lem latissime hianti; umbonibus terminalibus ; 

 latere antico hrevissimo suhtruncato ; latere postico 

 expanso lata ; valvd sinistrd ventricossimd ; lamina 

 cardinali complqnatd. 



The painted Mttilimeria. Shell somewhat rhom- 

 boidal, solid, painted with divergent brown lines, 

 very broadly gaping at the ventral margin ; 

 umboes terminal ; anterior side very short, rather 

 truncated ; posterior side expanded, broad ; left 

 valve very ventricose ; hinge plate flat. 



Sowerbt [Lyonsia). Proc. Zool. Soc, 1834, p. 88. 



Hab. Vancouver's Island. 



Species 7. (Mus. Brit.) 



Mttilimeria cuneata. Myt. testd temd, palidd, antice 

 injlatd, postice attenuatd, coinplanatd, latere postico 

 brevi, truncato ; umbonibus elevatis acuminaiis ; 

 margine dorsali rectiusculo, ventrali medio antice- 

 gue injlato. 



The wedge Mttilimeria. Shell thin, pale, inflated 

 anteriorly, posteriorly attenuated, flattened ; pos- 

 terior side short, truncated ; umboes elevated, 

 acuminated ; dorsal margin rather straight, ven- 

 tral in the middle and anterior side inflated. 



Gray. MS. Brit. Mus. 



Hab. ? 



