P L I C A T U L A. 



Plate I. 



Genus PLICATULA, Lamarck. 

 Testa unimuscuhsa, iiicequivnlvis, plicata, irnyuluns, 

 per (ipicem valvce dextrm adherens ; umbunes in- 

 aequaks, vix auricnlatce ; area cardinal^!, in vulva 

 dextrd parva ; dentes cardinales vtrdijue valvd 

 duoe, divergentes transverse striata; foveola lirja- 

 mentifera inter dentes ntrdque valvd triijona. 

 Shell with a single muscle, inequivalve, [ilaited ir- 

 regular, fixed by the apex of the right valve ; 

 umbocs unequal, scarcely auriculated ; cardinal 

 area in the right valve small; two divergent, 

 transverse, cardinal teeth in each valve striated 

 transversely ; a trigonal liL'aineiitiferous pit in 

 each valve between the teeth. 

 Plicatula is a well defined genus of shells always to be 

 recognised by the teeth and folds. Eight species were 

 described in the latest Monograph, that of the The- 

 saurus by Sowerby. Of the remaining five, two have 

 been described since, and three are here jircsented. 



The Philippines, Australia, New Zealand, and 

 the shores of Western America furnish all the species 

 described in this Monograph, with the exception of 

 Plicatuht Cei/lonica, and the little Pliatlula siiiiji/f.c 

 from China. 



Species 1. (Mus. Pirit.) 



PLICATfI..\ NOV^ ZF.LANDIiE. PH. tcstd temU, all) 



(lijirt.-'sii, ad laterd fuliaced ; plicis nui 



ob- 



tusis hinc-ilUc divisis, ad marginein dentiformibns. 

 The New Zealand Plicatula. Shell thin, white, 



depressed, leafy at the sides; jilaits numerous, 



obtuse, here and there divided, dentiform at the 



margin. 

 Sowerby. 

 Hob. New Zealand. 



The ribs are so divergent, that those near the dorsal 

 margin are at right angles with the central. 



s/rif/atd ; plicis panels, profiindis, angtdatis sim- 



pliribiis. 

 The simple Plicatula. Shell small, gibbous, thick, 



rather straight, somewhat ovate, of a golden 



brownish colour, sometimes striped ; plaits few, 



deep angular, simple. 



Gould. ? 



Hah. China. 



do 



Species 2. (Mus. Brit.) 

 Plicatula simplex. Pli. testa parvd, glbhd, crassd. 

 rectiusciild, suhovatd, fusco-suhaured, nonnunquan, 



October, 



The few plaits of this ap[iarently distinct species uu 

 "" extent, and consequently the shell 



not diverge to any c.-..n-in., .um v^^^noc 

 has a rather straight oval appearance. 



Plicatula peniciixat 



hnll, r on, 1,1, rii.j 

 hnnl.,,,. n,,t„n,i 



Si.ecies 3. (Mus. Brit.) 

 I'll 



sill [larvd, teinu, irregii- 

 ,' .iriilijiti'i. Hii, Is parvis, 

 jillris /ini/ir iHiirginem 

 ml nut IS, rnhirrliiils : iimnjln, v„lr,l lU.itr.i Irregu- 

 laritir dcidiculatd. 

 The pexcilled Plicatula. Shell small, thin, ir- 

 regularly ovate, rugose, minutely aculeatecl, 

 marked with small short chestnut lines; plaits very 

 small, very close near the margin ; margin of the. 

 left valve irregularly denticulated. 

 Carpextep.. 

 Hah. North America. 



Species 4. (Mus. Brit.) 



Plicatula imhuicata. Pli. tesld magnd, suhtrigond, 

 solidd, albidd, vel cirmamoned, lineis bi-evihus, 

 divaricatis, 7-iibescentibus notatd ; plicis magnis, 

 acute angulatis divaricatis, rarb divisis ; plerumqve 

 super angulum imbricatis. 



The imbricated Plic.\tula. Shell large, subtrigonal, 

 solid, whitish, or cinnamon, marked with short 

 divergent reddish lines ; plaits large, acutely 

 angular, divergent, rarely divided ; generally im- 

 bricated on tlie angle. 



Menke. Moll. Nov. IloUandia;. 



Hab. China, Philippines. — Honduras Bay, &c. 



1873. 



