Outlines of zoology . merous segments and (lo-2(>or more) foliaceous append-ages with respiratory shell is rarely absent,usually shield • like or bi-valved. The heart is a longdorsal vessel with numerousopenings. The eggs are ableto survive prolonged desicca-tion in the mud. Branchipus, a beautifullycoloured fresh - waterform, with hardly Brine - partheno-genetic. By graduallychanging the salinityof the water, Schmanke-witsch was able, in thecourse of several gen-,orations, to modify into A. mil-kausenii, and vice fert
Outlines of zoology . merous segments and (lo-2(>or more) foliaceous append-ages with respiratory shell is rarely absent,usually shield • like or bi-valved. The heart is a longdorsal vessel with numerousopenings. The eggs are ableto survive prolonged desicca-tion in the mud. Branchipus, a beautifullycoloured fresh - waterform, with hardly Brine - partheno-genetic. By graduallychanging the salinityof the water, Schmanke-witsch was able, in thecourse of several gen-,orations, to modify into A. mil-kausenii, and vice fertilis is oneof the four animalsknown to occur in thedense waters of , an archaic fresh-water form with a largedorsal shield. Apus is over an inch in length, a giant among Entomostraca. It hasan almost world-wide distribution. The appendages are verynumerous and mostly leaf-like. They may be regarded as-representing a primitive type of Crustacean limb. ProfessorRay Lankester enumerates them as follows:—. Fig. 153.—Dorsal surface oiAptiscancriformis. ?— From BronnsThierreich. In the anterior region are the two com-pound eyes, and behind them thesimple unpaired eye. The whip-likeoutgrowths of the first thoracic ap-pendage project laterally. f- Antenna. Pre-oral. V Second antenna. (This is sometimes absent, andapparently always in certain species.) 3- Mandible. Oral. - A- Maxilla. l5- Maxillipede. 300 PHYLUM ARTHROPODA. f6. First thoracic foot (leg-like).Thoracic J 7-16. Other ten thoracic feet (swimmers). (Pregenital). j The i6th in the female carries an egg-sac or brood- t chamber. There are eleven thoracic rings on the /17-68. Fifty-two abdominal feet, to which there corre-i Post-genital). \ spond only seventeen rings on the body. The large dorsal shield is not attached to the segments behind theone bearing the maxillipedes. Many of the thin limbs doubtlessfunction as gills. The genital apertures are on the sixteenthappendages. The anus is on t
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Keywords: ., bookcentury1900, bookdecade1910, bookidcu3192, booksubjectzoology
