Pomona College, Claremont. California 31 



subcylindrical portion extending to the still narrower introvert proper. The species is 

 like zostericota in laclving hoolis on the introvert, but differs obviously in the character 

 and arrangement of the tubercles. These are similarly small over the general body but 

 are more closely arranged over the middle region than over the broader posterior one, 

 while particularly characteristic is a band of abruptly much larger tubercles about the 

 base of the introvert, distad of which region ihey become again abruptly smaller. The 

 color is brown. The two retractors are inserted at the anterior end of the broad pos- 

 terior region and are fused anteriorly, their free portions short. Nephridia free. 



Length of body behind anus, 12 mm.; in front of this to base of tentacles, near 

 8 mm. 



Type— M. C. Z. 2, 184. 



DENDROSTOMA PYROIDES SP. NOV. 



Differing conspicuously from zostericota in form, being broadest at the posterior 

 end and as a whole subpyriform instead of conspicuously fusiform. It is darker brown 

 in color. A conspicuous external difference is in having the introvert, or proboscis, 

 armed on its median portion with numerous, comparatively large, dark hooks, which 

 are not definitelv seriate. The cuticle in general is covered with numerous small, dark, 

 rounded elevations which in surface view are circular to slightly elliptic in outline 

 and are larger in size at the base of the proboscis and at the posterior end of the body 

 than elsewhere. Tentacles arborescently branched, the terminal branches numerous, 

 finger-like. The two retractors are stout bands taking their origin in the posterior 

 third of the body. Contractile tube witli fewer caeca. Nephridia free, opening a little 

 farther forward than the anus. 



Length from anus to caudal end, 17 mm.; from anus to base of tentacles, S mm. 



Taken at low tide on Laguna Beach. 



Type— M. C. Z. 2, 182. 



PHASCOLOSOMA HESPERA SP. NOV. 



Somewhat resembling P. procerum in form, but with the proboscis more abruptly 

 set off from the body and on the average narrower and especially much longer relatively 

 to the latter. In the type the body proper is 8.5 mm. long, while the proboscis is 52 

 mm. long, i. e., about six times longer than the body, while in one paratype it is as much 

 as 7.5 times longer. The body of the type is 2.6 mm. thick and the proboscis half or 

 less than half this thickness. Body proper pointed at both ends, broadly subfusiform. 

 The skin at the caudal end of the body is rather thickly studded with papillae, which 

 are disally flat and dark colored over a pale and often constricted base. The papillae 

 rapidly become fewer and more widely scattered over the middle and anterior regions 

 of the bodv and over the proboscis, and at the same time become decidedly smaller and 

 are often borne singly on low, rounded elevations; on the proboscis th epapillae are 

 tvpically colorless. The two retractor muscles in the type have their origins in the 

 anterior part of the body. 



The type was secured in sand at Balboa, December 26, 1917. Paratyoes from eel- 

 grass on Laguna Beach, September, 1917. 



Type— M. C. Z. 2, 185. 



