THE TURBELLARIA 



uterus rudimentary ; ventral body musculature well developed (see 1 3, 

 26, 47). 



FAMILY 5. LEIMACOPSIDAE. Dorsal surface very convex ; mouth pre- 

 central. Leimacopsis, Dies. FAMILY 6. GEOPLANIDAE, v. Gr. Land 

 Planarians without tentacles or~snckers ; eyeless, or with many marginal 

 eyes. Geoplana, Stimpson (Fig. X. 3) ; Pelmatoplana, v. Gr. ; Choerado- 

 plana, v. Gr. ; Polycladus, Blanch. ; Artio- 

 posthia, v. Gr. ; Geobia, Dies. FAMILY 7. 

 BIPALIIDAE. Anterior end is broadened out 

 to form a semicircular cephalic plate ; mar- 

 ginal eyes. Bipalium, Stimpson (Fig. X. 1) ; 

 Perocephalus, v. Gr. ; Placocephalus, v. Gr. ; 

 P. keivensis, Moseley. FAMILY 8. COTYLO- 

 PLANIDAE, v. Gr., with sucker on ventral 

 surface anteriorly, and with two spherical 

 eyes. Cotyloplana, Spencer (57, Fig. X. 4) ; 

 Artiocotylus, v. Gr. FAMILY 9. RHYNCHO- 

 DEMIDAE, v. Gr., with two spherical eyes 

 anteriorly. Platydemus, v. Gr. ; Dolicho- 

 plana, Mos. ; Rhynchodemus, Leidy ; Micro- 

 plana, Vejd. ; Amblyplana, v. Gr. ; Nema- 

 todemus, v. Gr. ; Othelosoma, Gray. 



Further Remarks upon the Tridadida. 

 The distribution of these forms on 

 land, sea and fresh water, is of great 

 interest, though it remains to be seen 

 how far Hallez's classification on this 

 basis is justified. 



In general form they are flat and $ 

 leaf-like, though the terrestrial species 

 are usually elongated, some attain- 

 ing a length of nine or even fourteen 

 inches. Ferussac, 1841, appears to 

 have been the first to describe a land 

 Planarian from Brazil. Since that Triciads. 



. . i i f j i 2. Unicellular eye of Geoplana 



time they have been found in nearly ( a fte r Dendy). c, refringent portion 

 all parts of the world (by Moseley, Dar- J|^?iJa.J5lr ; "' p-plml 

 win, Dendy, etc.). The Triciads are ^Tf^X*? "Ctg m" 



CarnivOl'OUS and nocturnal. Their dlS- morons eye-spots (e) affd the row of 



ii, Spencer; 



ventral view of the anterior end. . s, 



tribution seems to indicate that they 



Q-ra anpipnr fnrin<a nPVprtTiplpx?*; thpv 



are ancient lorms , neverine ,ss, tney the preoral sncker . (After spencer. > 

 have in many respects lost their pnmi- b.Dicotyins puivinar, Grube; 



J r , dorsal view of the anterior end, show- 



tive characters, and present a greater ing ( S > the sucker on each side, (a> 

 degree of complexity and differentia- &Sgtft3S&"* 

 tion than do the Rhabdocoelida. The 



majority are longer and narrower than in other orders ; the anterior 

 end is frequently eared (Planaria), or with tentacles (Leimacopsis), 



