File:Image from page 177 of "Introduction to zoology; a guide to the study of animals, for the use of secondary schools;" (1900) (14785014635).jpg

Cerebratulus, a cream-colored nemertean

Identifier: introductiontozo00dave Title: Introduction to zoology; a guide to the study of animals, for the use of secondary schools; Year: 1900 (1900s) Authors: Davenport, Charles Benedict, 1866-1944 Davenport, Gertrude Anna Crotty, 1866- Subjects: Zoology Publisher: New York, Macmillan company London, Macmillian and co., ltd. Contributing Library: MBLWHOI Library Digitizing Sponsor: MBLWHOI Library

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Text Appearing Before Image: great epidemics of the flukes have occurred in this coun-try, a million sheep areannually lost by this para-site in Great Britain; andin 1879 and 1880 it wasestimated that three millionsheep died annually inEngland alone of thisparasite. In Buenos Ayres,during 1882, a millionsheep died of fluke disease.By great care in prevent-ing infection, especiallyduring damp seasons, wemay be able to prevent FiT A is allied to the flat worms. It includes chiefly marine animals, of somewhat flattenedform and great length, even as great as thirty metres.They protrude a long, slender proboscis. These wormsare especially abundant in the sand of the seashore,although land nemerteans occur. Cerebratulus (Fig. 148)is a common form from the east coast.

Text Appearing After Image: APPENDIX TO CHAPTER 159 APPENDIX TO CHAPTEPv X KEY TO THE MORE IMPORTANT FAMILIES OF POLYCH.^TA a\. Head distinct from trunk ; proboscis protrusible [wandering Polychseta].bi. With broad dorsal scales .... b-2. No scales ; only one mouth-segment. Ci. Cirri not leaf-like; body long and not flattened.d\. Head not segmented. e\. Jaws composed of many pieces .e-2- Two powerful jaws . d». Head with its lobes segmented . c2. Small worms, body flattened, cirri evident «o. Head not distinctly separated from trunk ; pro-boscis short, not protrusible ; no jaws [seden-tary Polychseta].bi. Gills, when present, arise either from almost all, or else the middle segments.GI. Body not separated into various regions ;distinct head; no antenna ; gills inform of elongated, thread-like cirri C2. Body divided into 2 or 3 different regions ;no antennal cirri; proboscis present;no gills &2- Gills almost always present and limited to the anterior end of the body ; no cirri; body divided into an anterior

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