ARTEMIS. 



Genus ARTEMIS, PoU. 

 Tfsia plus '/iiiiiiis orbicularis, cequivalvis, in^qtiiJaternlis, 

 concifiitrici striata ant lirata, raro lavis, Vm-s interdum 

 ad latent lamiiiatis, pracipue ad latiis posiicum, area 

 lit/ameiiti iiderdam simplici, plerumque plus minus 

 excavatd, latere antico plerumque lunulato, lunula im- 

 pressd. Cardo fortis, dentihus tribus divergeittibus in 

 valvd altera, in altera quatuor, Ugamento subexterrw. 

 Impressiones mmculares oblongce, subaquales ; pallii 

 sim'is impressio conspicue lanceolato-trigona, subprofim- 

 da. Testa plerumque albida. 

 Shell more or less orbicular, equivalve, inequilateral, 

 concentrically striated or ridged, rarely smooth, 

 ridges sometimes laminated at the sides, especially 

 at the posterior side, area of the ligament some- 

 times simple, generally more or less excavated, an- 

 terior side mostly impressly lunuled. Hiuge strong, 

 with three diverging teeth in one valve and four in 

 the other, ligament subesternal. Muscular- impres- 

 sions oblong, nearly equal ; impression of the sinus 

 of the mantle conspicuously lauceolately triangular, 

 rather deep. Shell mostly whitish. 

 The genus Artemis was introduced more than half a 

 century ago, upon anatomical gi'ouuds, by Poli. The 

 few species known to Linnasus, Chemnitz, and their con- 

 temporaries, were included under Venus, whilst Lamarck, 

 regardless of the views of the Neapolitan malacologist, 

 referred them to his genus Cytherea. Artemis differs from 

 both of these genera in the form of the foot, in the siphons 

 being united to their extremities, and in the mantle having 

 a lauceolately triangidar sinus, which is impressed in a 

 very characteristic manner upon the interior of each valve 

 of the shell. The peculiarities observable in the shell, in 

 addition to that of the pallial sinus, are its orbicular, com- 

 pressed form, its uniform concentric sculpture, and the 

 general absence of colour and pattern. The shell rarely 

 presents the polished smoothness or coloui'iug of Cytherea, 

 few species being so highly painted as the European 

 A. exoleta and its exotic analogue, A. varieyata ; neither 

 has it the festooned or serrated varieties of sculpture so 

 frequently presented in Venus. There is little variety in 

 the general aspect of the Artemides, but they are well 

 distinguished from each other in detail. 



The geographical position of the genus is mainly in 

 the eastern hemisphere. Of sixty-one species described in 

 this monograph, the localities of forty-six are known as 

 follows: — three inhabit the shores of Europe; five are 

 from Korea, Japan, and China ; eleven from the Philip- 

 pines ; two from the Moluccas, seven from Australia, 

 and two from New Zealand ; six from North Africa, 

 none being found on the shores of this continent below 

 the equator ; and seven only from America. 



April, 



The genus comprises about seven principal typical forms 

 of species, each of which affects a different locality. A. 

 concentrica and its congeners, the largest of the genus, 

 inhabit the shores of Central America, between West 

 Columbia and California ; another species of this type, 

 A. Patayonica, is recorded from the southern country 

 whose name it bears, but I have not been able to authen- 

 ticate this locality, and it seems doubtful. The remaining 

 American species, A. subquadrata, is from Peru, and of 

 very abnormal character; the shell being thin in sub- 

 stance, not symmetrically orbicular, and without a lunule. 

 The Australian species are typified by the characteristic 

 A. incisa, lamellata, and scalaris, the last of which is re- 

 presented in the Philippine Islands by A.jicvetiilis, whilst 

 A. varieyata is common to both these localities. A. plana, 

 from the coast of China, has the valves remarkably flat- 

 tened, and A. exasperata, from the Philippine Islands, 

 is the type of another interesting group in which the con- 

 centric ridges are thin, and raised at the sides, chiefly the 

 posterior, in squamate lamina;. A very singular form, 

 with a supplementary lunule, A. bilunulata, is found at 

 Japan ; and, on the shores of the Red Sea, a type of 

 totally different growth, contracted and gibbous, is repre- 

 sented by A. triyona. 



Species 1. (Mus. Cuming.) 



Artemis Isocaedia. Art. testa cordato-ovatd, altiore 

 quam lata, solidiusculd, yibbosd, coiicentrice acute stri- 

 ata, striis subirreyularibus, area liyamenti excamtd, 

 lunula cordatd, subampld, parum concavo-impressd ; 

 ylaucd, violaceo tinctd. 



The Isocardia Artemis. Shell cordately ovate, higher 

 than broad, rather solid, gibbous, concentrically 

 sharply striated, stria; somewhat in-egular, area of 

 the ligament excavated, lunule heart-shaped, rather 

 large, but little concavely impressed ; glaucous, tinged 

 with violet. ' 



Dunker, PhU. Abbild. and Besch. Conch. Cytl/. p. ;3(i. 

 pi. 8. f. 5. 



Ilab. ? 



A solid, gibbous, heart-shaped species, approaching in 



form to Chemnitz's figure of Venus contracta [Artemis 



coutracta, Philippi), which I have not been able to identify. 



Species 2. (Mus. Cuming.) 



Artemis lincta. Art. testa orbiculari, crassd, gibbusim- 

 culd, creberrimi leuuksimi et irreguluriter conceutrice 

 striata, slriis ad latera elevatiusculis, confertis, area 

 ligamenti subplanatd, parum excavatd, lunula obhngo- 

 cordatd, impressu. 



The sucked Artemis. Shell orbicular, thick, rather 

 o-ibbous, very closely, finely, and irregidarly cuiircn- 



