Polydora rickettsi — Woodwick 
81 
this worm suggest the species to be a boring 
form. Steinbeck and Ricketts (1941: 368) re- 
port the following for Spiro branchus incras- 
satus, the associated serpulid species, "An im- 
portant feature of the low intertidal landscape 
at Cape San Lucas, where the anastomosing 
calcareous tubes of this large and spectacular 
worm encrust the rocks.” 
REFERENCES 
Hartman, Olga. 1940. Boccardia proboscidea, 
a new species of spionid worm from Cali- 
fornia. Jour. Wash. Acad. Sci. 30: 382-387, 
i %. 
Rioja, Enrique. 1943. Estudios anelidologicos, 
VIII. Datos acerca de las especies del genero 
Polydora Bose, de las costas mexicanas del 
Pacifico. Anal. Inst. Biol. Mex. 14: 229-241, 
25 figs. 
Soderstrom, Adolf. 1920. Studien liber die 
Polychaeten Familie Spionidae. Dissertation, 
Uppsala. 286 pp., 1 pi., 174 figs. 
Steinbeck, John, and Edwin Ricketts. 1941. 
Sea of Cortez. Viking Press, New York, viii 
+ 598 pp., 41 pis. 
