A history of the British sessile-eyed Crustacea . ura, the alimentary canal is so arranged as to XXX INTRODUCTION. shut one part within another, so as to admit of the headbeing projected forward, that the animal might eat itsway into the wood that it penetrates/^ This we have notbeen able to verifj^, nor can we see the necessity for thedisarrangement of the stomach with all its attachments,when a prolongation of the oesophageal canal wouldenable the animal to accomplish the work on far easierconditions. The structure of the alimentary canal is longitudinallyfibrous. In the genus Ligia, a littl
A history of the British sessile-eyed Crustacea . ura, the alimentary canal is so arranged as to XXX INTRODUCTION. shut one part within another, so as to admit of the headbeing projected forward, that the animal might eat itsway into the wood that it penetrates/^ This we have notbeen able to verifj^, nor can we see the necessity for thedisarrangement of the stomach with all its attachments,when a prolongation of the oesophageal canal wouldenable the animal to accomplish the work on far easierconditions. The structure of the alimentary canal is longitudinallyfibrous. In the genus Ligia, a little anterior to the analtermination, a series of transverse muscular bands sur-round it without uniting on the under surface, audprobably fulfil the office of sphincter muscles. About two-thirds of the distance between the stomachand the telson, one or two appendages are attached to thealimentary canal in the Amphipoda. We say one or two,because we have distinctly dissected out two in Sulcalor(Fig. 5), but have failed to determine more than one in. Gammarus (Fig. 6), Maera, and other genera. The organis free at one extremity, and is borne in a forward posi-tion, resting on the dorsal surface of the primavia. Itis more important in appearance in some Amphipoda thanin others; in Sulcator it is very long. We have never seenit in any of the Isopoda that we have examined, but, as faras our experience supports us, it is present both in themale aud female Amphipoda, in the adult as well as in the INTRODUCTION. XXXI larval stage. In the younger form (Fig. 7) it is rudi-mentary, but scarcely more so than in Moera (Fig. 8).
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Keywords: ., bookauthor, bookcentury1800, bookdecade1860, booksubjectcrustacea
