PLATE X. 



Fig. I. Carinella spectosa. Portion of transverse section through nephridial 

 region. The ciliated nephridial canal {nep) shows the peculiar in- 

 folding of the integumental cells on its dorsal border. These integu- 

 mental cells are here loosely arranged, and show several deep infoldings 

 {op) which, under certain circumstances, may possibly have a more or less 

 distinct communication with the nephridial canal. But a small portion 

 of the closely packed gland cells in the integument are indicated. Ref- 

 erence letters are explained on p. S3. (X 75)- 



2. Carinella spectosa. Portion of a transverse section through the brain 

 region. The relation of the dorsal ganglion {dg) with the highly spec- 

 ialized cerebral sense organ [cso) is indicated. The ciliated canal {cc) 

 of the sense organ connects directly with the exterior by a narrow tube 

 {sop) — shown in dotted lines in the drawing, because it lies mainly in 

 another section — opening on the lateral margin of the head. Several 

 nerves {sn) are seen to pass from the dorsal ganglion to the sense organ. 

 Other reference letters as above. Only a small portion of the integu- 

 mental gland cells are shown. (X 75)- 



3. Amphiporics tigriiitcs. Dorsal view of anterior portion of body, cleared 

 in cedar oil. In front of the brain the arrangement of the ocelli is 

 shown, and farther back the position of the ovaries {ov). The intesti- 

 nal cceca are not indicated. Farragut Bay. ( X S). 



4. AmpJiiporus tigrinus. Median sagittal section through the anterior por- 

 tion of the body. The cephalic glands ( cgl ) lie above the opening of the 

 rhyncodaeum {ro). The mouth (■»/) separates from the proboscis 

 opening a little way back. The attachment («/) of the proboscis to the 

 tissues of the head is seen to be well in front of the brain commissures 

 (<fc and vc). The section shows the comparative size and arrangement of 

 the proboscis, blood vessels, esophagus, and other organs. Reference 

 letters as above. ( X 30) • 



(104) 



