516 REPORT ON ZOOLOGY, MDCCCXLIV. 



According to a notice communicated by Quatrefages 

 (Comptes rendus, 1844, p. 77 ; or Ann. d. Sc. Nat., t. i, 1841, 

 p. 20), Nemertes, in the disposition of its vascular system and 

 oral apparatus, approaches the Hirudinei, but in the confor- 

 mation of the sexual organs, and the csecal termination of 

 the intestinal canal, it recalls various Helminthes. 



VERMES TURBELLARIL 



Oersted has also supplied another great want in having 

 made, as far as was possible, a complete systematic classifi- 

 cation of the planariform worms. (Entwurf einer Eintheiluug 

 der Plattwiirmer.) He subjects Ehrenberg's classification of 

 theTuRBELLARTi to a just criticism, and correctly shows that 

 it cannot be deemed satisfactory. He conjoins the Planariae 

 with the Hirudinei, in a single order, the Apoda, which he 

 designates as the TREMATODINA. The Planarise constitute a 

 distinct tribe in this sub-order, which is thus characterised by 

 Oersted : Corpus plus minusve depressum, plerumque modo 

 paucies longius quam latius, ciliis vibrantibus obsitum et 

 mucosum. Systema nervorum et sgepe musculorum indis- 

 tinctum. Oculi, 2, 4, multi aut nulli. Cor nullum, sed vasa 

 distincta cum sanguine hyalino, flavescente vel etiam rube- 

 scente. Circulatio valvulis filiformibus (undulatione vasorum 

 nulla) fit. Tubus cibarius in corporis massam infossus, 

 simplex vel ramosus, tantum modo una apertura instructus. 

 Os plerumque exsertile. Androgyna aut sexu discrete. 

 Ovaria in distincta vel duo cava. Organum copulationis stimu- 

 landa? solidum, in utraque sexu ejusdem fornise. 



Dispositio Familiarum et Subfamiliarum. 



1. Tubo cibario ramoso. 



a. Ore maximo ferme piano (convexiusculo) . 



I. Earn. CRYPTOCCELA. 



b. Ore minore plus, minusve cylindrico. 



