486 allan hancock pacific expeditions vol. 10 



Characteristics of the Family Pilargiidae, emended 



The body is long, greatly flattened and ribbonlike (Pilargis) or some- 

 what depressed (Ancistrosyllis) or it is nearly cylindrical with inflated 

 (pi. 63, fig. 1) anterior segments (Loandalia and Talehsapia). It is 

 sometimes highly colored in life or it may be almost or quite colorless. 

 The prostomium is small and inconspicuous. It is provided with a pair 

 of massive (pi. 59, fig. 1) or smaller biarticulated palpi (Ancistrosyllis, 

 Pilargis, Loandalia) or the prostomium may be conical and smoothly 

 rounded in front (Talehsapia and Cabira). When palpi are present they 

 consist of a larger palpophore and a tiny, papillar or filamentous palpo- 

 style. Prostomial eyes are absent or may consist of one (pi. 62, fig. 1) or 

 2 pairs, located near the posterior margin on the dorsal side or laterally. 

 The prostomium has a pair of simple, smooth, short (pi. 59, fig. 1) to 

 long (pi. 61, fig. 1) antennae (Pilargis and Cabira) or also a median 

 antenna (Ancistrosyllis) or it totally lacks antennae (pi. 63, fig. 1) 

 (Loandalia and Talehsapia) . 



The surface epithelium is more or less closely papillated Pilargis and 

 some species of Ancistrosyllis or it may be somewhat areolated (pi. 63, 

 fig. 1 ) to smooth (some species of Ancistrosyllis, Loandalia, Talehsapia 

 and Cabira). 



The prostomium, where best developed among species of Ancistro- 

 syllis and Pilargis, consists essentially of a median and a pair of lateral 

 lobes. From its anterior ventral edge emerge the paired biarticulated 

 palpi which may be outgrowths of the first segment or peristomium. The 

 paired lateral prostomial lobes give rise to the paired antennae and eyes 

 if present; the median lobe is the origin of the unpaired antenna (pi. 62, 

 fig. 1). In one species (Ancistrosyllis rigida) the outer base of the palpo- 

 style has a small papilla ; this may be a peculiarity of the species. 



In so far as known the proboscis is eversible. In some genera it is 

 cylindrical when everted (pi. 63, fig. 1 ) and more or less highly muscular 

 (Ancistrosyllis, Loandalia and Talehsapia) ; in one genus it is globular 

 when everted and epithelial (Pilargis). When cylindrical its distal edge 

 may be provided with soft papillae arranged in 1 (pi. 61, fig. 2) or 2 

 rows or the edge may be smooth. In all species of the family save that of 

 Talehsapia there are no jaws in so far as known. The proboscis remains 

 unknown for the genus Cabira. 



The dual nature of the proboscis in species of one family is not without 

 parallel since Eisig (1914) has as demonstrated comparable phenomena 



