53* 



to be found in one and not the other. lh? range of varia* 



tlon in egg size is also different. One range of variation 



mm. 

 is frcra 0.0912 to 0.134/the other from 0101 to 0.111 aim. 



Since ^ghino3toiaa revolutum was firt found by 

 Free lion in the goose, and later "by 2eder, I*oose in the 

 goose and duoV oaid by others snd myself, the type with 

 the thirty *seven spines,! thin*", should be oalled by the 



If* 9CXT9 



abov<* name and a new nara@ chosen for the one with the 



'- *-*.-l'1' &tt 'ttU'0 



thirty -four spines found in the shore bird, Machetes 

 j3ugnax I nuggeat the name .'Sohinpa to ma limiGolJ. L The large 



Pi t*5,p'*<:.t 



number of primary hosts assigned to this speoies by different 

 I feel quite sure is due to plaoing two or more 

 under the one n<3e 



Theoretical Dl^ouseion of the Life Cycle. 



are th^^^i egg miraoidiuffl uiother*redia f daughter* 



redia, ceroaria, encysted ai^araodistciae (cyst) and adult* 

 To acotnaplifch this life oyols only two hosts are neoessary, 

 the snail Phy& ; ., Q.cqidetitjBuli.s and a du<d or $ooae Apparently 

 any duolr and perhaps any goose forma a suitable host, since 

 the adult eohinostomes were raised experimentally in mongrel 

 dueKlin,;8t ^ere found in the Amerioan soaup due?, Marl la rnarila 

 on Stow LaJ'e and have "been reported froia many other ducks 

 and gi*8e in many places in the northern hemisphere. As 

 stated, Pfo/sa QQOidj*ntali8 usually serves aa both the inter* 

 aediat-e and secondary intermediate host. This eohinostcrae, 

 however, is not apeoific sin? the encysted '\gamc distoiae stage 

 has also been found in another species of snail and plan aria* 



