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U.S. NATIONAL MUSEUM BULLETIN 227 



Figure 23. — Alciopidae, Alciofa reyyiaudii: a, ventral view anterior end with 2 large 

 papillae of proboscis projecting from mouth; h, parapodium, posterior view. 



Family Tomopteridae 



Exclusively pelagic. Body colorless, transparent, crystal clear, 

 segments few, without distinct segmental lines or septa. Setae lack- 

 ing except for a single internal seta in each of one to two pairs of 

 anterior modified tentacular cirri. Prostomium and tentacular seg- 

 ments fused to form a head region provided with a pair of diverging 

 flattened anterior antennae, a short pair of tentacular cirri (may be 

 small, inconspicuous or lacking, fig. 25a), a large pair of tentacular 

 cirri which may be longer than the body, a pair of ciliated epaulettes 

 or nuchal organs near the bases of the tentacular cirri, 2 deep-set 

 eyes close to the oval cerebral ganglion (visible due to the trans- 

 parency of the body) . 



Parapodia of trunk region longer than the body is wide, without 

 setae or acicula, distally bilobed, each ramus bordered with a flattened 

 finlike membrane or pinnule bearing glands of various kinds, referred 

 to as rosette organs (yellow or brown spheres with a darker center; 

 with fatty globules blackened by osmic acid; thought to be lumines- 



