1 28 SOLENJLDJE. 



inferiorem (interiorem) tegens, inferior crassior, prope dentem 

 lateralem anticum, baud curvatus, altior exteriore ; dextra} 

 singuli ; pauluin curvafci, parte sinistra ascendente tenues, parte 

 dextra desceudente incrassati ; clentes laterales in valva sinistra 

 bini, erecti, antice triangulafci ; postice uncinati, valva dextra bini 

 postici et bini antici, bini exteriores (11011 semper exstantes) 

 minimi ; interiores longi, triangulati. antice crassiores. 



Affinis Pis. scholtzii, Clessin*, differt forma dentium cardin. 

 valvse sinistrse, situ deutium cardinalium, minore profund. 



Hob. Lake Walar, Kashmir. 



The author appears to have only been able to see two perfect 

 specimens -which were both very young, lie therefore gives the 

 following measurements taken from a series of single valves : 



The proportion between length and breadth is therefore 3'1 



to 2-8. 



Family 



Subfamily SOLENIN^S. 



Shell equivalve, transversely elongate, more or less gaping at 

 each end, covered with a periostracum ; umbones not prominent; 

 ligament external, on an elongate ridge; hinge very variable, 

 bearing from one to three cardinal teeth on each valve ; lateral 

 teeth wanting ; adductor scars in both valves distant ; pal Hal 

 impression posteriorly more or less sinuous, pedal impressions 

 well marked beneath the umbones or near the dorsal margin; 

 external surface of the shell presenting a well-defined cellular 

 structure, consisting of long prisms, very oblique in relation to 

 the surface and showing the presence of nuclei ; internal surface 

 nearly homogeneous ; non-nacreous. 



Animal, with the exception of Novaculina, marine or estuarine ; 

 siphons usually short, in part united or entirely separate ; foot 

 large, powerful, more or less cylindrical, elongated ; without any 

 trace of byssogenous organs ; palpes variable in size ; gills straight, 

 unequal, lengthened and enclosed in the branchial siphon. 



Distribution . World- w i de . 



P. scholtzii, Clessin=P. olitusale. 



