204 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 19 



Euchone limicola is an estuarine form, limited to harbor areas, in 

 sand}^ mud. 



Family SERPULIDAE 



Genus Spirobranchus Blainville, 1818 



Spirobranchus spinosus Moore, 1923 



(Plate 7) 



Spirab ranch us spinosus Moore, 1923 :248-250, pi. 18, fig. 47. 



Collections : Isthmus Cove, Santa Catalina Island. 



This brilliantly multi-colored serpulid is one of the conspicuous en- 

 crusting forms along the leeward side of Santa Catalina Island, and along 

 outer, rocky insular coves of? southern California. Its hard, stony, white 

 tubes encrust rocky walls at and below intertidal levels. When the ani- 

 mals are extended, they present a variety of red and white banded, or 

 black, blue and brown banded crowns. A slight disturbance at the surface 

 will cause the entire colony to withdraw, revealing the purple-white 

 tubes; these are longitudinally ridged and often diffused with red and 

 blue pigments along the ridges. 



The only known account of this species was made from a single 

 imperfect specimen, 23 mm long, taken off Santa Barbara Island, in 29 

 fms, in fine yellow sand and coralline rock (possibly only from the coral- 

 line rock). Because of its abundance at Santa Catalina Island, the species 

 is here more fully described. The body of adult specimens measures 20 to 

 25 mm long, the radioles being 6.2 mm long. AVidth in the thorax is 2.5 

 mm and in the collar region 4 to 5 mm. The tentacular crown has paired, 

 inrolled halves; each consists of 45 to 50 radioles, coiled in about three 

 spirals, and the lateral pinnae are paired with the longest outermost and 

 the shortest innermost and most distal. The radioles are basally united by 

 a palmate membrane for about two-fifths of the total length. 1 he oper- 

 cular stalk is unpaired (Fig. 1), formed of the dorsalmost left radiole ; 

 it terminates in a broad, circular, calcareous disk which extends distally 

 to near the ends of the radioles; the disk has a pair of smaller inner 

 branched spines (Fig. 2), and a pair of larger outer branched spines. 

 The pedicle is cylindrical for half its basal length, then has a pair of 

 broadly expanded lateral wings which extend distally to near the base of 

 the distal disk. The operculum is sometimes partly overgrown with other 

 organisms, especially bryozoans, spirorbids, sponge masses, etc. 



1 he collar membrane is large, consists of a pair of long, broad, dor- 

 solateral lobes, a pair of much smaller lateral lobes, and a pair of large 



