518 REPORT ON ZOOLOGY, MDCCCXLIV. 



Twenty- three to twenty-five species are enumerated in 

 these five genera, including scarcely any than niariue Pla- 

 narire, amongst which are two new species, Leptoplana niyri- 

 pundata and Typhlolepta caca, from the coast of Denmark. 

 The description of the family Dendroccela runs as follows : 



Corpus plerumque valde depressum. Tubus cibarius 

 ramosus. Oris apertura in medio vel post medium corpus. 

 Os cylindricum in cavitate propria liberum, margine tanturn 

 posteriore ad tubum cibariuin affixum, valde exsertile. 



Dispositio Generum. 



1. Corpore linear!, oculo unico. 



1. Genus Monocelis, Ehrb. 



2. Corpore oblongo oculis duobus aut niultis. 



a. Oris apertura in medio corpore. 



* Tubi cibarii ramis arbusculiformibus. 



2. Genus Dendroccelum, Oerst. 

 ** Tub! cibarii ramis indivisis oviforuiibus. 



3. Genus Planaria (Muller), Oerst. 



b. Oris apertura extremitati posticse proxima. 



4. Genus Tdostoma. Oerst. 



Oersted enumerates eleven different species in this family, 

 one of which is new. Besides the well-known freshwater 

 Planarise, we also find amongst them some marine forms. 

 The family Rhabdoccela, lastly, is thus described : 



Corpus subdepressum vel tereticusculum. Tubus cibarius 

 simplex. Apertura oris terminalis vel infera. Os ampho- 

 riforme vel annuliforme, minus liberum quam in familia 

 antecedent!. 



Dispositio Subfamiliarum et Generum. 



a. Ore cyliudrico horizontals 

 * Oris apertura terminali. 



Subfamilia I. PROSTOME^:. 



1. Genus Prostoiita, Oerst uon Duges. 

 Oris apertura noii terminal!. 



Subfamilia II. DEROSTOME.E. 



