PROCEEDINGS OF THE UNITED STATES NATIONAL MUSEUM 
SMITHSONIAN INSTITUTION 
U.S. NATIONAL MUSEUM 
Vol. 97 Washington: 1947 No. 3218 
NEW GENERA AND SPECIES OF ECHIUROID AND 
SIPUNCULOID WORMS 
By Watter Kenrick FIsHEr 
Tue types of the new species of worms described herein are in 
the collection of the United States National Museum. I am indebted 
to Dr. Olga Hartman for the two new echiuroids, to Prof. G. E. 
MacGinitie for the specimens of the remarkable Siphonomecus ingens, 
and to the Museum of Comparative Zoology for three specimens of 
Sipunculus branchiatus W. Fischer for which I have made a new genus. 
Phylum ECHIUROIDEA 
Genus THALASSEMA Lamarck 
THALASSEMA PHILOSTRACUM, new species 
PLATE 8 
Diagnosis.—Nephridia 4; nephrostome conspicuous, semicircular, 
without spirals; dorsal blood vessel posteriorly voluminous, the ring 
vessel at junction of fore-gut with intestine; fore-gut long, longer than 
the presiphonal segment of intestine; the latter of moderate length; 
verrucae of skin unequal, low, transversely lengthened, and serially 
arranged in middle region of body; setae with interbasal muscle, the 
hook small and sharply curved; lower lip of mouth not formed by 
thick margin of proboscis, which is ventrally cleft at its base; length 
12 to 21 mm. 
Description.—Body wall rather thin in expanded parts, slightly 
translucent; verrucae not prominent, arranged in transverse series in 
the middle region of body and there transversely elongated. In some 
758332—47——1 351 
