DISTRIBUTION AND STRUCTURE OF THE EPIDERMAL 

 SENSE ORGANS IN THE TADPOLES OF 

 RANA CLAMITANS. 



BV WM. KORDES BOWEN. 



The larvae of many amphibia possess epidermal sense organs similar 

 to the lateral line organs of fishes. This report deals briefly with the 

 structure and distribution of the lateral line organs of the tadpoles of 

 liana clamitans, from which species they have not heretofore been re- 

 ported. The species was determined by illustrations and descriptions in 

 Wright's "North American Anura." 



The tadpole possesses several rows of lateral line organs, which are 

 located chiefly on the dorsal and lateral surfaces, although a few extend 

 onto the anterior ventral surface. The distribution conforms to a definite 

 system, with minor individual variations. These rows are made up of a 

 series of light colored dots, each dot representing one or more of the 

 sense organs. While the sense organs usually occur singly or in pairs, 

 six or eight are sometimes found side by side. Kingsbury believes 

 that such groups of sense organs are produced by fission from a single 

 original sensory structure. 



Laie 



rai 



Dorsal 



Figure 1. Tadpoles of RaiKi clamitans, showing distribution of sense organs. 

 Length, 4 cm. 



Distributiou. Beginning from a point slightly behind the eye, two 

 diverging rows extend backwards along the body and the tail. The inner 



19th Mich. Acad. Sci. Kept., 1917. 

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