148 PROCEEDINGS OF THE NATIONAL MUSEUM vol.85 



NEPHTYS CAECOIDES, new species 



Figure 63 



Nephthys coeca Johnson, 1001, p. 401 (part). 



NepJithys caeca Moore, 1909, p. 243; 1911, p. 243; 1923, p. 257 (part).—? 



Treadwell, 1914, p. 192 (part).— ? Hilton, 1919, p. 27. (Non Fabricius, 



1780, p. 304. ) 

 Nephthys assimiJis Treadweix, 1914, p. 193 (part). {Non Malmgren, 1865, p. 



105.) 

 fNephthys malmgreni Treadwell, 1914, p. 192. {Non ThM, 1879, p. 26.) 



Length to 100 mm; width 5 to 8 mm; number of segments about 

 120 ; trim, stiff, slender in appearance. 



Prostomium trapezoidal or somewhat rounded anteriorly (fig. 63, 

 ff, 6) ; with characteristic dusky brown pigmentation pattern in life, 

 persisting through preservation; postectal margins of prostomium 

 with a pair of prominent nuchal papillae (fig. 63, a). 



Proboscis subdistally with 22 rows of papillae and a median dorsal 

 papilla ; proximally smooth, glistening. Recurved cirri first present 

 from fourth setiger, continued posteriorly almost to end of body; 

 fifteenth last segment as in figure 63, h. Recurved cirri exceeding their 

 respective dorsal cirri except in last nine segments, where recurved 

 cirri are smaller than dorsal cirri. 



Parapodia as in figure 63, e-h; dorsal and ventral cirri of first 

 parapodium somewhat flattened triangular (fig. 63, e). Setae of 

 three kinds : Slender, barred, in preacicular fascicle ; simple, capillary ; 

 and bristled, capillary in postacicular fascicle. Bristled area of the 

 latter extensive (fig. 63, e, d), extending almost across width of setae 

 where best developed. 



Eolot7/pe.—V.S.l^M. no. 20319. 



Dktriljution. — Tomales Bay, Calif, (type) ; Bodega, Bolinas, San 

 Francisco, Morro, Half Moon and Newport Bays, and Elkhorn 

 Slough, Calif.; Wallochey Bay, Wash, (one individual collected by 

 E. F. Ricketts). Common in muddy sands and eelgrass flats, con- 

 trasting therein with the habitat of N. calif orniensis (see below), 

 which abounds in cleaner, coarser sandy beaches. N. caecoides seems 

 to replace the polar N. caeca (Fabricius) in more temperate waters. 

 In numerous collections studied the latter has been encountered only 

 once from California, the former only once from the north Pacific 

 (Washington). 



Systenmtic discusswn.— Moore (1911, p. 243) identified numerous 

 individuals from California as N. caeca, stating, however, that 

 "scarcely a single specimen can be said to be typical AL caeca,''^ and "I 

 am by no means convinced that more than one species may not be 

 represented." Monro (1933, p. 51) described a Nephthys sp. as a 

 tropical representative of N. caeca but said tliat it showed certain 

 differences from the typical form. Johnson's N. coeca (1901, p. 401) 



