12 ENTOZOA. 



special tmgs being transmitted to tlie pits or depressions occurring 

 on either side of the head which, moreover, have been described 

 as "respiratory fossae." The habits of the Nemertidge have been 

 amusingly descanted on by Dalyell, Montague, Rymer Jones, 

 Gosse, and others, but we now stand in need of a careftd reinvesti- 

 gation of the anatomical peculiarities, development, and relations 

 of the entire group. 



Genera. — Nemertes, Cuvier ; Polia, DeUe-Ohiaje ; = Baseodis- 

 cus, Diesing ; = Borlasia, Oken ; = Tceniosoma, Stimpson ; = 

 Valencinia, Quatrefages ; = Quatrefagea, Diesing ; Polyhopla, Die- 

 sing ; Meckelia, Leuckart ; = Notospermus, Huschke ; Notogymnus, 

 Hemprich and Bhrenberg ; OpMocephalus, Quoy and Gaimard ; 

 Colpocephalus, Diesing; Ghlamydocephalus, Diesing; Astemma, 

 Oersted ; Polystemma, Bhrenberg ; HemicycUa, Hemprich and 

 Ehrenberg ; Ommatoplea, Bhrenberg ; AmpMporus, Bhrenberg 

 GephalothriXf Oersted; Emea, Leidy; Tetrastemma, Ehrenberg 

 ? Heeate, Girard; Serpentaria, Goodsir; Garinella, Johnston 

 Linneiis, Sowerhj; PLiwews, Beattie and Gray; Cerebratulus, denier 

 Micrura (and larval Pilidium), Ehrenberg; Acrostoma, Grube 

 Diplomma, Stimpson ; Nareda, Girard ; Oerstedia, Quatrefages 

 Tatsnoskia, Stimpson; Polina, Stimpson; Gosmocephala, Stimpson 

 Bamphogordius, Rathke ; Stimpsonia, Girard ; Lobilabrum, Blain- 

 ville ; Prorynchus, Schultze ; Tuiulanus, Renier ; ? Beneria, Girard ; 

 ? Siphonenteron, Renier ; Leodes, Girard ; Biplopleura, Stimpson ; 

 Gephalonema, Stimpson ; Ditactorrhoehma, Diesing ; Loxarrhochma, 

 Schmarda ; Emplectonema, Stimpson ; ? DicMlus, Stimpson ; 

 ? Lumbricaria, Milnster ; ? Nemertites, Murchison ; ? Gololites, 

 Agassiz ; ? Medusites, Germar. 



In the briefest possible manner I have thus designedly sketched 

 the typical and leading family characteristics of the TurbeUaria, 

 simply for the purpose of communicating a clear conception of the 

 true position and affinities of this singular and comparatively little 

 known class of worms. As before hinted, much remains to be 

 accomphshed in the way of our rightly understanding the visceral 



