244 



BULLETIN: MUSEUM OF COMPAEATIVE ZOOLOGY. 



i 



length when sexually mature. Ocelli number perha]js 20 or more 

 on each side of head ; they are irregular in shape and variable in 



size, and are arranged in two irregular and 

 indistinctly separated clusters on each side of 

 head (Text-fig. 49). 



Color of body of various shades of lemon, 

 yellow, and yellowish brown, much influenced 

 at time of sexual maturity by color of genital 

 products, giving rise to marked sexual color 

 varieties. When sexual products are mature, 

 the prevailing color of females is yellowish 

 orange obscured to a great extent, except in 

 eso})hageal region, by the dark olive green 

 color of the mature ova. The dark green 

 ovarian pouches commonly api)ear as irregu- 

 lar lateral transverse stripes of dark green 

 alternating with the yellow color of body. 

 Males are pale yellowish with a slight tinge 

 of greenish, and when sexually mature the 

 spermaries appear as numerous cream colored 

 dots. The position of proboscis sheath is 

 indicated in esophageal region by a narrow 

 median longitudinal dorsal stripe of brownish 

 color in both sexes. 



Proboscis armature remarkably weak ; cen- 

 tral stylet small and short, but acutely 

 pointed ; basis short, thick, rounded behind, 

 of double the length of stylet (PI. 25, fig. 

 201). There are commonly about 5 acces- 

 sory stylets in each of the two lateral pouches. 

 Glandular wreath about stylet region of a 

 deep green color, which persists even after 

 mounting in balsam. 



Cerebral sense organs small, situated slightly in front of brain. 

 Intestinal caecum broad, but terminates anteriorly far behind brain 

 region. 



Further anatomical peculiarities are given in the pa])er cited. 

 Habitat. — As yet known only from Farragut Bay, British Co- 

 lumbia, where it occurs under stones in muddy situations at about 

 half tide (Coe, : 01, p. 48). 



Fig. •iQ. — Aviphiporus ti- 

 griuus. Dorsal view 

 of anterior portion of 

 body, cleared in cedar 

 oil, showing position of 

 ocelli, brain, proboscis, 

 and ovaries. 



