126 COE 



I. Length 15 cm. or more ; verj' pale brown or whitish, with two 

 longitudinal dorsal stripes of deep brown ; proboscis provided 



with eight nerves N. gracilis^ p. 142. 



II. Body moderately elongated ; proboscis sheath about one-half to 

 three-fourths the length of the body ; central stylet well devel- 

 oped Pat'anemeries . 



I. Four or six pouches of accessory stylets ; proboscis with ten 

 large nerves. Translucent, pale orange anteriorly, flesh color, 

 grayish or very pale salmon posteriorly, color much obscured 

 by deep green of intestinal tract P. californica^ p. 144. 



III. Body very small and slender ; two ocelli ; proboscis but little 



developed, central stylet minute ; no accessory stylets ; parasitic 



on crabs Carcinonemertes , 



I. Only 4-6 mm. long when sexually mature; color orange or 

 reddish ; parasitic on the egg masses of Epialtus and per- 

 haps other crabs C. epialti^ p . 151. 



IV. Body rather short and thick ; proboscis sheath reaches nearly or 



quite to posterior end of body ; proboscis large, central stylet 

 well developed. 

 aa. Ocelli do not extend posteriorly beyond the brain ; basis of cen- 

 tral stylet usually rounded posteriorly. 

 h. Body not very small. Ocelli usually numerous. 



Amfhiporus . 



1. Rather slender, 10-25 mm. in length; yellow; very con- 



spicuous red blood vessels ; five to ten ocelli in single 

 row on each side of head ; basis very slender, about same 

 length as stylet A. crtcentatus, p. 154. 



2. Slender, 50-90 mm. in length; proboscis sheath about 



six-sevenths the length of body ; proboscis with fifteen 

 nerves ; basis of same length as stylet ; ocelli numerous. 



A. pazilimis^ -p. 155. 



bh. Body very small. Ocelli few; usually four well developed 



ocelli arranged in a rectangle TctrasteJtima. 



1. Rather slender, 15-25 mm. in length, reddish-brown 



both above and below, except head, which is white 

 with sharply marked wreath of deep brown color on 

 dorsal surface. Blood corpuscles red. 



T. signifer^ p. 156. 



2. Usually 30 to 70 mm. in length ; head provided with 



two pairs of very conspicuous, lateral, oblique fur- 

 rows. Color very variable, except head which is 



