WOOD worth: ILLINOIS TURBELLARIA. 



Smaller spots of deep brown or black occur scattered over the surface among 

 the larger patches. In the largest, oldest specimens there are very few or none 

 of the clear areas. Frequently a light median streak more or less free from 

 pigment occurs, extending backward from between the eye-spots (Fig. 3). 

 Length 4 to 9 mm., greatest breadth ^ to 1| mm. 



Station D ; 13,011, Station C ; 13,113, Illinois R. at Havana; 22,050a, Sta- 

 tion E ; 13,521, Station L; 22,020, Station K ; 22,033d, Station L ; 22,011c, 

 Station L ; 22,053, Station H. 



Planaria maculata is the commonest of our fresh-water Planarians and was 

 the first one to be described (Leidy, 1848) ; however, nothing has been pub- 

 lished regarding its sexual organs, and I am unable to ofi'er anything in this 

 regard ; not one of the hundreds of specimens that came under my observation 

 was sexually mature. The species, as already mentioned, is sluggish, seldom 

 being in motion in the aquaria, and when stirred up in company with P. gono- 

 cephala and P. dorotocephala it is the first to come to rest. It is possible, as 

 also suggested by Leidy (1885, p. 50), that it is nocturnal in its habits. It is 

 usually found on the protected sides of stones, of empty Unio shells, or of 

 aquatic plants, and often huddled together in large numbers. 



About 40% of the Illinois individuals that I examined exhibited mutilations 

 at the anterior or posterior ends, either by the absence of a head, or by being 

 truncated posteriorly. In the cases where the posterior end is lacking the 

 pharynx, instead of occupying a position midway between the anterior and 

 posterior ends, extends almost to the posterior limits of the animal. There is 

 no pigmentation about such scars. I have elsewhere (1896% p. 240) referred to 

 the mutilations in Planaria mdculata, and suggested that they were the result 

 of reproduction by transverse division. I have since learned from Dr. Harriet 

 Randolph that the species divides spontaneously, and that small fragments from 

 any part of the body will regenerate into a new worm.^ 



1 Through the courtesy of Dr. Randolph I am able to present the following 

 table. The material upon which tlie experiments were made was collected on the 

 island of Naushon, Vineyard Sound, Mass. 



* Whole number isolated on August 17 and 18 was forty individualB. 

 t From which the Planarians came. 



