514 REPORT ON ZOOLOGY, MDCCCXLIV. 



and in most zoological treatises scarcely anything lias here- 

 tofore been said about them. On which account also the 

 Reporter is induced to give in this place the families and 

 genera instituted by Oersted, together with his diagnoses. 



In the first place, he considers the Nemertini as a sub-order 

 of Vermes apodes, which sub-order is designated by him as 

 CESTOIDINA, and is characterised as follows : Corpus lineare 

 teretiusculum rarius depressum, multo longius, quani latins, 

 indistincte armulatum, mucosum, ciliis vibrantibus obsitum ; 

 niusculi distincti, non vero nervi (?). Oculi 2, 4, 6, 8, 10, 

 multi, vel nulli. Organ a respiratoria specialia nulla, vel 

 fissurse respiratorise laterales in capite aquse ad cordum parietes 

 aditum conciliantes. Circulatio completa et corda duo. Tubus 

 cibarius simplex cum oris apertura infera (rarius termiuali) 

 et ano terminali. Os nullum exsertile. Sexus duo, in 

 utroque organum copulationis stiniulandse. Testiculi et 

 ovaria cava ne minimum quidern forma inter se discrepantia 

 tantum uiodo contento (ovulis aut spermatozois), complura 

 in utroque latere uniuscujusque segmeuti. These Cestoidina 

 are divided by Oersted into two families, with eight generas. 

 These are : 



Fam. I. NEMERTINA. Os inferum, anus terminalis. 



(1.) Corpus filiforme, utrinque sequaliter atteuuatum 

 (caput nullum distinctum), fissurre respiratorire uullse. 



Os et ovaria aut testiculi ab apice valde remota. 



1 Gen. Cephalothrix Oerst. with two species. 



Os et ovaria aut testiculi ab apice non multo remota. 



2 Gen. Astemma Oerst. with two species. 



(2.) Corpus lineare teretiusculum, antice plus minusve 

 dilatation (caput distinctum), fissurai respiratoria3 distincta? 

 aut nullre. 



. Caput a corpore coustrictum, fissurae respiratorise 

 nullse. 



3 Gen. Borlas'ia (Oken) Oerst. with eight species. 



b. Caput a corpore non constriction, fissura? respiratorise 

 plus miuusve distinctse. 



o. Oculi numerosi acervati. 



