4 DR. J. WILHELMI. 



landi Girard (3) described a second new marine triclad 

 from Boston Bay, Vortex ivarrcni n. sp., for which 

 later he established the new genus Fovia (7). Verrill 

 (10) in 1873-74 described the same species as Plaiiaria 

 grisea n. sp. and later as Fovia littoralis n. sp. (11). The 

 descriptions of these species and of the genus Fovia are insuffi- 

 cient. Already in 1857 Stimpson ^ classed the European P/au- 

 aria affinisO^. with the genus Fovia and Verrill (12) identified the 

 preceding North American species with Stimpson's Fovia affijiis 

 (Oe.) as varieties ivarreni andgrisea. Girard (3) meanwhile cites 

 Fovia warroii as a marine triclad (with anus) and classed the 

 identical Fovia grisea with his new rhabdoccelid (!) genus A^eo- 

 plana. From the North European Fovia affinis I studied the 

 only three existing individuals of the Museum of Bergen and 

 showed ^ that probably it is a fresh-water form, which sometimes 

 occurs also in brackish and sea-water, perhaps Planaria torva 

 Miill. The American species Fovia warreni and grisea (lit- 

 toralis ^) spoken of by Verrill as Fovia affinis (Oe.) belong to 

 only one species of the genus Procerodes, which must be desig- 

 nated Procerodes warreni (Giv.) ; the variations of color not being 

 greater than usual in sea- and fresh-water-planarians, do not 

 allow of forming separate varieties ; the genus Fovia must be 

 included in the genus Procerodes. Girard (4, 7, 8) described it as 

 viviparous : the larvae resemble the adult animal, but its anterior 

 end is less truncated. Eyes are still absent in the larva:;, but the 

 position of these is indicated by two transparent spots ; a canal 

 in the middle of the body is interpreted as the alimentary tube. 

 These " larvae " are protozoans [Hoplitophrya), living in the 

 cavity of the pharynx and in the intestine of triclads. M. 

 Schultze ^ found them in Procerodes {Planaria) ulva; of the Baltic 

 Sea and described them under the name of Opalina uncinata. I 

 myself found them in large numbers in Procerodes segmentata 



' Stimpson, W., " Prodromus, etc., Proc. Acad. N. Sc. Philadelphia, 1857. 



2 Wilhelmi, J. " Ober Planaria affinis Miiller." Bergens Museums Aarbog, 

 1907, Nr. 4. 



3 1 collected them at Woods Hole and neighborhood and at Massachusetts Bay, 

 summer, 1907. 



* Schultze, M., " Beitrage zur Naturgeschichte der Turbellarieti," i. Abtheilung, 

 (Jreifswald, 1851. 



