62 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 15 



The arrangement of the organs on the proboscidial sheath is fixed. 

 The distal pore is subdistal and directed away from the paragnathal 

 end; the side with cuticular ridges (when these are present) is also 

 abgnathal. 



Up to now the fundamental kinds of these organs have not been 

 used to effect a major grouping of the many species in the genus Glycera, 

 although Arwidsson (1899, p. 22) allied certain species with G. con- 

 voluta Keferstein. Based on the materials examined, the species may be 

 recognized for 4 groups. 



In one group of species, the proboscidial organs are transversely 

 ridged on one side (pi. 10, fig. 1). The following species are of this 

 kind: G. dibranchiata Ehlers, G. oxycephala Ehlers, G. robusta Ehlers, 

 G. lapidum Quatrefages, G. tenuis Hartman, and perhaps also G. 

 chirori Izuka. 



In another group of species, the proboscidial organs have an en- 

 veloping sheath or membrane (pi. 10, fig. 6). The following species 

 are of this kind: G. africana Arwidsson, G. alba (Rathke), G. cirrata 

 Fauvel (not Grube), G. convoluta Keferstein, G. manorae Fauvel, 

 G. onomichiensis Izuka, G. prashadi Fauvel and G. tridactyla Schmarda. 



In a third group of species the proboscidial organs are tall, slender 

 and supported by strong, chitinized strands (pi. 10, fig. 11). To it 

 belong G. tesselata Grube, G. papulosa Grube, possibly also G. amboin- 

 ensis Mcintosh and G. longipinnis Grube. 



In a fourth group of species, all the organs are soft and oval, elongate 

 or subspherical in shape; they lack visible surface ornamentation. The 

 following species are believed to belong here: G. americana Leidy, G. 

 branchiopoda Moore, G. capitata Oersted, G. edwardsi Gravier, G. 

 gigantea Quatrefages, G. guinensis, Augener, G. kerguelensis Mcintosh, 

 G. lancadivae Schmarda, G. rouxli Audouin and Edwards, G. subaenea 

 Grube and G. unicornis Savigny. 



Species of Glycera are widely distributed in littoral regions. About 

 23 species are recorded from the Western Hemisphere. Six (or 7) are 

 known from both Atlantic and Pacific shores, including G. alba, G. 

 americana, G. capitata, G. dibranchiata, G. oxycephala, G. tesselata 

 and possibly G. robusta. Eighteen species have been recorded from the 

 Pacific side of the Americas ; in addition to those mentioned above, they 

 are G. branchiopoda, G. carnea, G. convoluta, G. fundicola, G. gigantea, 

 G. lancadivae (but see list below), G. longissima, G. martenseni, G. 

 mexicana, G. papulosa, G. rouxii and G. tenuis. The following species 

 are recorded only from the Atlantic shores of America: G. canadensis, 



