66 BUREAU OF ANIMAL INDUSTRY. 



It is somewhat difficult to arrange hosts in an order of preference in 

 respect to this point, but we may recognize the following groups as 

 approximate, at least: 



First series: Homo sapiens, Sus scrofa domestica, Mus musculus, 

 Mus rattus, Mus decumamis, Bos taurus, Ovis aries, Gallus </'/////*, 

 Musca domestica, Blatta, Phyllodromia. 



Second series: Canis familiar is, Fells catus domestica, Equas cabal- 

 lus, Anas boschas, Anser cinereus, Culicidse. 



Third series: Rana temporaria, R. esculenta, Bufo. 



Fourth series: Animals found in Europe and North America. 



Fifth series: Marine or Australian animals. 



Sixth series: Animals found in Asia, Africa, or South America. 



It is not contended that the above list is without criticism or that it 

 may not be viewed from different standpoints, according to local con- 

 ditions, but the general idea advanced will doubtless appeal to many 

 workers in parasitology. 



21. REMAINING GENERA MENTIONED IN THIS PAPER. 



In the foregoing pages it has been shown that certain species must 

 be taken as type for certain genera, and that certain other species may 

 best be taken as type for certain other genera. 



There now remain certain generic names, for some of which (for 

 various reasons) we prefer not to definitely propose types at this time. 

 We shall, however, indicate the species which might best serve as 

 type unless contraindicated by some circumstance which does not 

 occur to us at present. As these suggestions are made with reserve, 

 the indication should not be construed as designation of type. 



Acanthopharynx Marion, 1870; probably affinis, because both niale and female are 



given. 

 Acanthophorus Linstow, 1876; probably tennis by page precedence. As the generic 



name is a homonym, it can not hold, but the designation of a type might 



influence some later generic name. 

 Amblyura Hemprich & Ehrenberg, 1828; probably serpcntulus, by page precedence, 



male and female mentioned, and more extensive mention than gordius. 

 Amphistenus Marion, 1870; ? agilis, by page precedence. 

 Anguillulina Gervais & van Beneden, 1859; probably tritici, page precedence; and 



on basis of Railliet, 1893a, 553. 

 Aorurus Leidy, 1849; ? agile, by page precedence. 

 Ascaridia Dujardin, 1845; ? truncata, by page precedence. 

 Calodlum Dujardin, 1845; ? annulosum,, because of its hosts (Mus rattus and M. decn- 



manus) ; the rats had lived on onions (Allium cepa). 

 Cephalacanthus Diesing, 1853; probably monacanthus, by page precedence and because 



the host ( Tenebrio molitor) is so common 



Crenosoma Molin, 1861; probably striatum, by page precedence, and figured. 

 Crossophorus Hemprich & Ehrenberg, 1828; ? collaris, by page precedence. 

 Cucullanus Mueller, 1777; see pp. 96-97. 

 Cystoopsis, see p. 98. 



