WORMS 167 



GENUS Planaria 



P. grisea. Oval or ftlliptical in form j anterior end truncate : poste- 

 rior end rounded ; color yellow or gray, with a light stripe ; two black 

 eyes surrounded with white : length one half to three quarters of an 

 inch ; width about one eighth of an inch. Found under stones between 

 tide-marks. 



GENUS Procerodes 



P.frequens. One eighth of an inch long; brown or black above, 

 gray below ; has two kidney-shaped eyes ; active and abundant. Found 

 under stones near high-water mark. 



GENUS Sdelloura 



B. rustica. Body milk-white, smooth, thin. Found on Viva latissima 

 (sea-lettuce). 

 B. Candida. Parasitic on the gills of the horseshoe-crab. 



GENUS Fovia 

 F. Warrenii. Bright red, narrow, oblong. Found on eel-grass. 



ORDER KHABDOCffiLIDA 



Minute, active worms found among the red seaweeds. They 

 are brown in color, and are marked by one or more transverse 

 white bars. 



CLASS NEMERTINEA 



The nemerteans are long, narrow, flat, smooth worms, and 

 vary from one half of an inch to many feet in length. They are 

 exceedingly contractile, and when alarmed can shrink to less than 

 half their normal length. They are very generally distributed, 

 and are to be found between tide-marks, in loose coils like a 

 string, under stones on sandy and muddy shores. The very 

 long species, like Linens marinus, are solitary, bat other smaller 

 species are gregarious, many worms being coiled together in 

 tangled masses. Some species are to be found in empty shells, 

 and others live among the seaweeds. They are very slimy, the 

 epidermis secreting an abundance of mucus, and they can often 

 be tracked by the trail of slime they leave behind them. This 

 mucus sometimes hardens, forming for some species a tubu- 



