. The Tanganyika problem; an account of the researches undertaken concerning the existence of marine animals in Central Africa . Fig. 42.—Semi diagram of the anatomy of Spekia zonata. The heart has the regular tsenioglossate characters. InS. zonata, owing to the naticoid shape of the body, thereis a forward displacement of the internal viscera, whichresults in the pulmonary vein not going directly forward tothe base ot the stenidium, as in Tanganyicia rnfofilosa andmost other Prosobranchs, but in its being bent slightlybackwards in a more or less acute curve before it reachesthe base of the gi
. The Tanganyika problem; an account of the researches undertaken concerning the existence of marine animals in Central Africa . Fig. 42.—Semi diagram of the anatomy of Spekia zonata. The heart has the regular tsenioglossate characters. InS. zonata, owing to the naticoid shape of the body, thereis a forward displacement of the internal viscera, whichresults in the pulmonary vein not going directly forward tothe base ot the stenidium, as in Tanganyicia rnfofilosa andmost other Prosobranchs, but in its being bent slightlybackwards in a more or less acute curve before it reachesthe base of the gill. This relative displacement of theheart and gill is fully described by Haller in the NaticasTrochita radians, Ergcea plana, Crepidula peruviana(Lam.), Tanaais ungiiiforniis (Lam.), and Crucibuhun(sp. ?), and it is curious to find that this displacement has 17* 26o THE TANGANYIKA PROBLEM. proceeded less in Spekia than in any of the fornis whichHaller figured The gill in S. zonata is very much like that of the genus cryst. Fig. 43.—Semi diagram of the anatomy of Spekia mantle cavity has been opened from above, and thenerves are represented in black. Opposite st the stomach ;stn. the gill ; c}yst. s. the crystalline style. Tanganyicia. The leaves are similarly broad, low, andtriangular, and their apices are prolonged into the samelittorinoid finger-like processes. Such processes are figured by Haller in the gills of
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectm, booksubjectzoology
