PIGET SOUND NEMERTEAXS. 



211 



Fig. 21. Atnphipo- 

 rus formidabilis. 

 Free-hand from 

 living wonn. 



10. Amphiporus formidabilis n. sp. 



Length in alcohol 9 + cms. Breadth 2 mm. Form and 

 color as in preceding species except for flesh-colored tinge 

 anteriorly. Visceral region dull gray. Eyes ver^^ numerous 

 (ioo-i50=b), distributed in three groups, one 

 antero-lateral paired group and one median un- 

 paired group. The latter is V-shaped and situ- 

 ated just in front of brain, with the limbs directed 

 backwards and merging into two gray streaks 

 that extend along each side for a varying distance 

 caudad (fig. 22). 



Internal Anatomy. Mouth opens into rhyn- 

 chodeum. Head densely packed with cells of 

 cephalic gland. Cephalic commissure just pos- 

 terior to proboscis-pore. Cephalic organs in front of brain, op- 

 posite mouth, canals open laterally behind proboscis-pore. In- 

 testinal caeca extend to brain. Nephridia open by numerous 

 efferent ducts, some of which open dorsally, others laterally. 

 Integumentary glands abundant in anterior portion of body. 

 Rhynchocoel extends to end of body. 



Central stylet shorter than its basal 

 portion. Marginal stylet-pockets ar- 

 ranged in a continuous row around the 

 central stylet. Their number appears to 

 be either 8 d= or 1 2 d= . Each contains 

 two stylets. 



In number and arrangement of the 

 marginal stylet-pockets this form bears 

 close resemblance to A. spiiiosissivms 

 Burger and A. piignax Hubrecht, but 

 differs in numerous anatomical points 

 from A. spinosissiunis, especially in the 

 position of the excretory pores. 



Habitat and Distribution. On piles 

 of wharves, and on stones and rocks 

 along with A. imp avis piiiosiis and Emplectoncma viridc. Puget 

 Sound and Alaska. 



Fig. 22. AmphipoTiis for- 

 Diidabilis. Camera lu- 

 cida from worm under 

 influence of chloral hy- 

 drate under cover-slip. 



