228 SOLENll).^. 



inferiorem (iuteriorem) tegens, inferior crassior, prope dentem 

 lateralem anticiiui, liaud curvatus, altior exteriore ; dextraD 

 singuli ; paulum ciii-vati, parte sinistra ascendente tenues, parte 

 dexti-a descendente incrassati ; dentes laterales in A^alva sinistra 

 bini, erecti, antice triangulati ; postiee uncinati, valva dextra bini 

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

 minimi ; interiores longi, triangulati, antice crassiores. 



Affinis Pis. scJioltzli, Clessiu*, diiSert forma dentium cardin, 

 valvse sinistrpe, situ dentium cardinaliuin, minore profund. 



Jhih. Lake Walar, Kashmir. 



Tbe author appears to have only been able to see two ])erfect 

 specimens which were both very young, he therefore gives the 

 following measurements taken from a series of single valves : — 



1. 2. 8. 4. 5. 6. 



r Long. . . 3 3 3 2-7 2-G — mm. 



-„. '-'^ , ^ Lat.' .. 3-5 3 3-2 3 29 3-4 mm. 



Kight Valves. I -pj,^^^^^^ 11111 M mm. 



1. 2. 3. 

 rn, fLong. .. 2-7 3 2-4 mm. 



T /-i^T ^ J-'-it. .. 3 3-1 2-8 mm. 



Lett Valves. y^- -, i i i 



[Diam... 1 1"1 1 m!n. 



The proportion between length and breadth is therefore 3-1 

 to 2-8. 



Family SOLEMD.E. 



Subfamily SOLENIN^. 



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 ; pallial 

 imi)ression posteriorly more or less sinuous, pedal impressions 

 well marked beneath tlie 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 jS'ovaculina, marine or estuarine ; 

 siphons usually short, in part united or entii-ely 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-wide. 



* P. ^choltzii. Clessin = P. ohtusale. 



