The Cambridge natural history . divided into (a) Diotocardicf^(Raliotis, Fissurella, Trochus, Nerita, Patella), which have, orwhose immediate ancestors are believed to have had, twoauricles to the heart, two sets of breathing organs, two kidneys,but no proboscis, penis, or siphon, and (?>) Monoto-cardio,^ in which the hearthas only one auricle, thetrue breathing organ issingle, and there is a singlekidney. To this divisionbelong the great majorityof marine univalve Mol-lusca, Cypraea, Bvxci-nurn, Murex, Littorina,lantliina, all the land andfresh - water operculates{Ci/clostoma, Melania
The Cambridge natural history . divided into (a) Diotocardicf^(Raliotis, Fissurella, Trochus, Nerita, Patella), which have, orwhose immediate ancestors are believed to have had, twoauricles to the heart, two sets of breathing organs, two kidneys,but no proboscis, penis, or siphon, and (?>) Monoto-cardio,^ in which the hearthas only one auricle, thetrue breathing organ issingle, and there is a singlekidney. To this divisionbelong the great majorityof marine univalve Mol-lusca, Cypraea, Bvxci-nurn, Murex, Littorina,lantliina, all the land andfresh - water operculates{Ci/clostoma, Melania, Fa-iled ina, etc.), as well as the Ifcterojwda, which are a group ofProsobranchiata which have betaken themselves to a pelagic life. (3) In the Opisthohranchiata^ the breathing organs (whenpresent) are heJtind the heart, and the auricle of the heart isconsequently behind the ventricle. They are asymmetricalmarine animals; usually, but by no means always, without asliell, scarcely ever with an operculum in the adult state. The. Fig. 4.—Example of ;mediterranea Lam.,branchia ; /, foot ;J), penis ; s, sucker Heterojiod, Carinaria Naples : a, amis ; br, intestine ; m, mouth ; sh, shell ; t, tentacles. The auimal swims foot uppeimost. ^ TToXis, many ; 7r\d^, plate. - irpdaw, in front. Often alluded to in the sequel as opereulate Gasteropoda. ^ KTividiov, a little comb. ?* dvu, two; , single ; Sira, auricles; Kapdia, heart. ? o-maOiv, behind. 10 CLASSIFICATION OF GASTEROPODA sexes are united in the same individual. The Ojnsthohrcmchiatafall into two divisions : (a) Tectihranchiata, in which the In-eathingorgan is more or less covered l)^ the mantle, and a shell isusually present, which is sometimes rudimentary, Bulla,
Size: 2002px × 1248px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1890, booksubjectzoology, bookyear1895
