356 



FRESH-WATER BIOLOGY 



89 (90) Color blackish to purplish or brownish by reflected light, blackish 

 or gray by transmitted light. With many irregular spots 

 entirely free from pigment. . Planaria maculata Leidy 1848. 



Length 15 mm. Immature specimens average about 8 to 

 II mm. In small specimens the pigment occurs in isolated 

 patches and spots. In larger specimens the pigment patches 

 are confluent chiefly in the median region leaving the clear 

 irregular areas which give a ver>' spotted appearance to the 

 animal. Smaller spots of deep brown or black scattered 

 among the larger patches. Frequently with a light median 

 streak. Posterior half of cephalic appendages with non- 

 pigmented spots. Ventral surface much lighter than dorsal, 

 almost entirely free from pigment. Reproduces freely by 

 transverse fission posterior to pharynx. Sexually mature 

 specimens not common in most localities. Sluggish. Much 

 less active than those nearly related species which might 

 be confused with it. Found commonly among algae and 

 water plants or under stones where water is comparatively 

 quiet. Mass., Penn., 111., Mich., Neb. 



Fig. 630. Planaria maculata. U) From life. X 6. (After Wood worth.) (5) Sexual organs, dorsal 

 view: u, uterus; co, common oviduct; od, oviduct; a, atrium; gp, genital pore; p, cirrus; vd, vas de- 

 ferens; m, mouth. X about 35- (After Curtis.) 



90 (89) Color dark reddish-brown to grayish-brown. Uniformly pigmented. 



Planaria gonocephala Duges 1830. 



im 





Greatest length 25 mm. 

 Usually not over 15 mm. 

 Girard describes the color 

 of this species as often of 

 a blackish -brown. Pos- 

 terior margins of auricular appendages free from 

 pigment. Much lighter on ventral than on dorsal 

 side. Eyes in a plane joining the apices of the 

 auricles. Clear areas around eyes sometimes 

 elongated in an antero-posterior direction. Re- 

 production asexually common. Mich., 111. 



Fig. 631. Planaria gonocephala. (^) From life. X S. 

 (After Woodworth.) {B) Sexual organs, longitudinal 

 section side view: ui, uterus; od, oviduct; de, ductus 

 ejaculatorius; ^a/), papilla; i'(/, vas deferens; ag, genital 

 atrium; vs, vesicula seminalis; m, mouth; utd, duct of 

 uterus; pdr, cirrus glands; pdr^, ducts of cirrus glands; 

 gP, genitfvl pore. Much enlarged. (After Bohmig.) 



91 (86) Anterior end rather sharply pointed. Angle formed by lateral mar- 

 gins of head not more than 60°. Cephalic appendages long, 

 slender, sharply pointed, with anterior margin shorter than 

 posterior margin. Body distinctly narrower back of ceph- 

 alic appendages than just in front 92 



