250 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 10 



SylHs altemata Moore 



Moore, 1908, pp. 323-325, figs, a-f ; Berkeley, 1938, pp. 37-38. 



At Second Sled Road, Dillon Beach, it is found among algae and in 

 Mytilus beds; at Tomales "Point, ocean side, it is in sponge and Bryozoa 

 clumps. In life it is usually pale, with segments crossed by narrow trans- 

 verse black lines, segmentally arranged. Length is 20 to 30 mm. 



Typosyllis pulchra (Berkeley) 



Syllis pulchra Berkeley, 1938, pp. 34-35, fig. 1. 



At Second Sled Road, Dillon Beach, this was collected from Mytilus 

 colonies by Hai-vey I. Fisher. The dorsum is chocolate brown, cirri are 

 pale. Dorsal cirri have as many as 50 to 70 articles each, the successive 

 rings closely crowded. An asexual stolon is present on many individuals ; 

 it occurs singly, from any one of the following segments: 42, 43, 45, 47, 

 49, 52, 53, or 59. The stolon consists of about 25 setigers. Length is 25 

 to 30 mm. 



Pterosyllis, species 

 Fauvel, 1923, p. 279. 



Several fragments come from Tomales Point, ocean side. 



Exogone, species 



Fauvel, 1923, p. 305; Berkeley, 1938, p. 44. 



At Dillon Beach and surrounding vicinities, this occurs among algae, 

 sponge, and hydroid growths. It is one of the smallest syllids in these 

 areas. External gestation is typical. Length is 4 to 7 mm. 



Family Nephtyidae 

 JCey TO Species 



1. Smaller; prostomium and first few segments with broad, dark 

 pattern on the dorsal side Nephtys caecoides 



1. Larger; prostomium with spread eagle pattern; first few seg- 

 ments usually pale dorsally; inhabits fairly clean sandy beaches 

 Nephtys calif orniensis 



Nephtys caecoides Hartman 



Hartman, 1938, pp. 148-149, fig. 63. 



This is common in Tomales Bay and Bodega Lagoon, in muddy sand 

 flats. Length is 80 to 100 mm. 



