124 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 15 



Furcate setae (fig. 4) are first present from about the sixth segment 

 and continue posteriorly through most segments in both notopodia and 

 neuropodia. The 2 tines are about equally long and thick ; the strengthen- 

 ing fibers extend along the inner sides of both tines, though directed 

 somewhat away from the center; the 2 tines are nearly symmetrical. 

 The pygidium terminates in a long, median cirriform process. 



In a second group of individuals (see under Collections, above), the 

 interramal cirri are not present before segment 7 or 8. The postsetal 

 lamella of notopodia tends to be somewhat superior instead of immedi- 

 ately behind the setal fascicle. In other respects, however, including the 

 peculiar details of the proboscis and the diffusely spinous setae, the 

 specimens agree with those described above. It is further noteworthy, 

 that among 6 individuals from one station (1265-41) some smaller, 

 15 mm long individuals have interramal cirri first present from segment 

 5, whereas the largest one, 44 mm long, does not have them before 

 segment 8. 



A. dicirris grossly resembles A. dibranchis (see above) in some 

 respects, and some individuals were earlier (Hartman, 1940, p. 237) 

 so identified. In both the prostomium has a pair of dark eyespots near 

 the posterior margin ; neuropodia have a long, erect lobe on the superior 

 edge. In A. dicirris, however, the proboscis has 22 rows of papillae 

 whereas in A. dibranchis there are 14 rows (which may however be 

 secondarily divided proximally). The proximal surface of the proboscis 

 is diffusely papillated in A. dicirris and presumably smooth in A. di- 

 branchis (Grube). 



Nephthys dibranchis Monro (1933a, p. 56) from Gorgona Island, 

 Panama in 20-30 fms, is here referred to A. dicirris since the proboscis 

 has 22 rows of subterminal papillae with none distinctly medial; inter- 

 ramal cirri are first present from segment 5 and continued back on 

 most body segments. Other records of N. dibranchis from tropical or 

 subtropical parts of the Eastern Pacific are perhaps also this, thus Neph- 

 thys dibranchis Berkeley (1941, p. 340) from Santa Cruz Island, Cali- 

 fornia. It is likely also that Nephthys verrilli Cowles (1931, p. 340) 

 from Maryland, belongs to this species. 



Holotype. — from station 436-36 and paratypes in the Allan Hancock 

 Foundation. 



Type locality. — Pinas Bay, Panama, shore (station 436-36). 



Distribution. — A. dicirris occurs in warm waters of both sides of 

 tropical and subtropical America and the Gulf of California, Mexico; 

 it extends north at least to southern California in the west and Beaufort, 

 North Carolina or possibly Maryland on the Atlantic side; its known 

 range is intertidal to 72 fms. 



