Notes on the Sipiinculida of l^aguna 

 Beach 



RALPH V. CHAMIIERI.IX 

 The followiiii; notes ami provisional diagnoses are based upon a collection 

 of Sipunculids made hv Prof. Hilton at Laguna Beach in 1917. Six species are 

 represented. 



SIPUNCULUS NUDUS LIXN. 

 One specimen of this widespread species was taken on the sand Hats at low tide 

 in August, Balboa. As preserved it is 26 cms. long. Attachments of nephridia and 

 retractor muscles normal. The usual 31-32 longitudinal muscle bands. The body 

 appears to be pigmented to some extent, as has also been recorded for a specimen from 

 the Malacca region described as dark brown (Selenka), and one from Key West 

 (Cierould). The species is known from various parts of the Atlantic along both shores, 

 from the Mediterranean, .Adriatic and Red seas, Malacca, Bismarck Archipelago, 

 Philippines and Japan. 



r-HVSCOSOMA ACA.SSIZII ( KEFKRSTEIN) 



In the collection are six specimens of this well-marked species taken at low tide 

 on sand flats at Balboa and I.aguna Beach. The species is otherwise known to occur 

 along the California coast (e.g., at Monterey Bay, Mendocino, San Francisco, Crescent 

 City) and northward (Vancouver Id.) as well as southward (Puntarena, Panama). 

 It has also been taken at Loyalty Is., Ceylon, Laccadives and Maldives, and in the 

 Atlantic on the coasts of the I'nited States and .Africa. 



DENDROSTOMA ZOSTERICOI.A SP. XOV. 

 This species belongs to the group with but two retractor muscles. These have 

 thifir origins in the posterior third of the body (in the type about 10 mm. from caudal 

 end) and are well developed ihroi'ghout and free to near insertions. The nephridia 

 open at the level of the anrs and are elongate and free. Contractile tube with numer- 

 ous caeca. 'I'entacles strongly dendritic or arborescent, the terminal branches numerous. 

 Introvert wholly lacking hooks. Skin brown or in part grey, set off into numerous 

 arras, these transversely elongate in middle region, in the posterior more rectangular 

 and longitudinally elongate. Kntire body and introvert, excepting a short area proximad 

 of tentacles, bearing moderately numerous, small, dark and rounded elevations which do 

 not rise into true papillae; usually one of these to each cuiicular area; of uniform size 

 and abiniiance throughout. Body typically narrowed at both ends, fusiform. 35 mm. 

 long behind anus anil about 15 mm. to distal end of introvert. 



Taken in eel-grass in September, l'>17. 



Type— M. C. Z. 2, I XI. 



OENDRIISroM \ MVTHElTA SP. NOV. 

 The type of this species was found in eel-grass (Zostera) in the same original 

 lot with the types of the preceding species. It is a smaller species of obviously different 

 form. The body is widest at the posterior end, followed by a much longer, narrower, 



