. Text book of zoology. Zoology. Sub-Class 1. Entomostraca. Order 1. Phyllopoda. 195 Limnadia, etc., afford a transition to tlie next order; they are distinguislied by having the carapace divided into two movable halves, provided externally with a very hard cuticle, and surrounding the whole body; the valves shut together as do those of Lamellibranohs, for which they might be mistaken. Further, the lateral eyes are very near one another or even united; the second antennse are very strong and provided with two jointed filaments, the exopod and the distal part of the endopod respectively, whilst
. Text book of zoology. Zoology. Sub-Class 1. Entomostraca. Order 1. Phyllopoda. 195 Limnadia, etc., afford a transition to tlie next order; they are distinguislied by having the carapace divided into two movable halves, provided externally with a very hard cuticle, and surrounding the whole body; the valves shut together as do those of Lamellibranohs, for which they might be mistaken. Further, the lateral eyes are very near one another or even united; the second antennse are very strong and provided with two jointed filaments, the exopod and the distal part of the endopod respectively, whilst the first antennae attain only a small size. Order 2. Cladocera. The Daphnids must be regarded as peculiarly developed Phyllopoda with a small number of limbs^ and a large compressed bivalve carapace enclosing the body with the append- ages ; upon the head there is a large compound eye, which is mounted upon a short stalk and is movable; it arises from the fusion of the lateral eyes, and is enclosed in a special socket, formed by the upgrowth of a fold of skin; there is usually also a small unpaired nauplius-eye. The first antennsB are generally short, and provided with olfactory hairs. The second antennae are powerful biramous natatory organs. Besides the mandibles. Fig. 156. A Daphnid, Stda CTj/s'aHina, with eight winter eggs in the brood-pouoh. a, first, a^ second, antenna, an anus, d gut, h heart, m mouth, o eggs, oe eye, ov ovary, r caudal fork, S carapace.—After "Weismann. there is a feebly developed pair of maxillge. The short thorax is provided with laminate nectopods like the limbs of the Phyllopoda, though there are only four to six pairs. The abdomen is curved dovmwards, and has two pointed, unsegmented caudal appendages at the tip. There is a powerful pulsatile heart anteriorly and dorsally, 0 2. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illu
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectzoology, bookyear1896
