184 



[Note. The different species of Tetrarhynchiia are, according to 

 V. SIEBOLD, nothing else than imperfect and sexless forms of tape- 

 worms, which in the perfect and developed condition belong to the 

 genus Rhyncobothrius of RUDOLPHI. These last are found only in 

 the intestinal canal of Rays and Sharks. The embryos of Rhynco- 

 botkrii make use of the bodies of other marine animals on which 

 Kays and Sharks feed, as a temporary residence, until they attain 

 to the intestinal canal of the latter by being swallowed together 

 with their host. Such animals are Flat-fish, the Turbot, Barbel, 

 Haddock, Gurnard, Conger-eel, Sepia ; in all of which young Tetra- 

 rhynchi have been found. That in such situations they find only 

 a temporary abode is proved by their being so frequently encysted, 

 and by their restless state, for they perforate the flesh, the walls of 

 the stomach, and the substance of the different organs, digging and 

 boring with their four proboscides that can be forced in and out, 

 and are covered with innumerable recurved hooklets. VON SIEBOLD 

 Band und Blasen-wilrmer, pp. 43, 44.] 



Family II. Acantliocephala. Body utricular, roundish, marked 

 with transverse rugae. Mouth none; proboscis retractile, covered 

 with recurved hooks. Sexes distinct. 



Echinorhynchus MUELL., KUD. 



Spiny-snouted worm. This genus (the only one of the family 

 and of which the characters, therefore, coincide with those of the 

 family) abounds in species which occur especially in the intestinal 

 canal of vertebrate animals (mostly of birds and fishes). 



The largest species lives in the small intestine of the wild and tame hog, 

 Echinorh. gigas CLOQUET Anat. des vers inteslinaux, PL 5 8, BREMSER 

 Icon. Helm. Tab. vi. figs, i 4. See for the anatomy CLOQUET'S work ; 

 comp. BUROW Echinorhynchi strumosi Anatome. Diss. Zootom. Regiomonti, 

 1836, 8vo. This Echinorh. strumosus lives in the small intestine of 

 different species of Phoca. 



Family III. Trematoda. Body depressed or roundish, soft. 

 Suctorial pores. Mouth distinct; nutrient canal divided, mostly 

 ramose. All the individuals hermaphrodite. 



Distoma RETZ., ZED. (Fasciola L. in part). Body soft, depressed 

 or roundish. Two suctorial acetabula ; one terminal anterior, with 

 perforated base leading to the mouth, the other ventral, situated not 

 far from the former, impervious. 



