lOO 



wliorl is also sculptured with numerous obliquely-curved longitu- 

 dinal plicie; rostrum oi moderate length. Aperture elongately 

 sub-oval; sinus rather deep, and not very wide; canal open, 

 moderately wide, and slightly curved. 



Length,' 32; width, 11 millim. 



Hab. :— Mouth of Tugela River N. by W., distant 1 8 miles. Depth, 

 S5 fms. Bottom, mud , . 



This shell somewhat resembles P. gciiuiiata. Hinds, but it is 

 larger and somewhat different in detail. It also seems to have 

 affiViitv with tlie much larger Chinese species /'. Kirncri. Doumet. 



PLKi'KOTo.NiA MAKMOK.viA, T.amarck, Anim. .'^. \ crt. \\\- p. 95. 

 Rccvo, Lonch. icon (Pleur.) fig. Ji . .'. war. inacuhila). 



The shells resemble in colour and i)attern those which are 

 prcttv abundant in the China Sea, 1 'liili])pincs, &c-,, but the keel 

 is less prominent. 



Hab- : — Same as last- 



I iKKii i;i.i.\ I'l NCTICULATA, Sowcrby, Proc. Zool. Soc, 1870. 

 p. 253, .Marine Shells of South .\fnca (,IMate V. fig- 102). 



Several small specimens obtained in large trawl in St. Francis 

 Bav. Lat , i,4"2' 45" S. ; long., 25° 10' P.. Depth, 30-34 fms- 



SiLKiiA I'oi.ir.^. Wood (= 7'. Jupoiiica, Dunker). 



Hab. :— Amatikulii River mouth N.W. by N., distant 10 mi'es. 

 Depth, 24 fms. Bottom, sand and shells. 



This species is very widely distributed- The Japanese and Red 

 Sea shells can scarcely be distinguished, and though the South 

 . African specimens sent me not being Uilly develoiu'd, are smaller, 

 thcA- are m other respects similar. 



Arca (i')Aur.Ai-i.\') i.ACTF.v YAK- cn'.T.A, Krauss (Plate IP ilg. 

 1 P). Sud Afric, .Moll- ]>. i6. 



Hab. :— Durnford Point, Natal, N.K. by E., distant 9 miles. 

 Depth. IT, fins, 'dredeed . Bottom, sand and shells, bard ground. 



Pi figuring this variuy, I intended to givt' it a si)ccific name, 

 relying ])rii;cii)allv upon ils obesity of form and its small 

 diam()n(k.slKi])ed ligameni. Pi)on comi)ariiig, lunvexer, a large 

 number of s])ecimens of -/ /(/(■/(■(/ -I'.ritisli. Mediterranean, and 

 South .\frican — 1 tind them to var\ so nuicli in the form of the 

 shell, as well as in the size and shai)e of the ligament, that I am 

 constrained to adopt Krauss' view that this form is nothing more 

 than a \arietv. 



■:o: 



Publi!-hed 25111 Septumlier, 1O02. 



