NO. 1772. ANNELIDS OF THE ARENICOLID.JE—ASHWORTH. 31 



gills, of the neuropodia and especially of the oesophageal glands; we 

 may therefore conclude that the Alaskan species has little affinity 

 with the antarctic one. A. glacialis agrees with A. raarina in the 

 number of its nepliridia, its neuropodia, oesophageal glands, septal 

 pouches, statocysts, and statoliths, but differences are noticeable in 

 regard to the number of chaetigerous segments and pairs of gills and 

 in the character of the gills, though the gills of A. glacialis may almost 

 be regarded as an extreme form of the bushy type of gill seen in 

 many specimens of A. marina. A. glacialis and A. cristata agree in 

 the number of their segments and pairs of gills and in the character 

 of the neuropodia in their branchial region, but they differ in respect 

 of the size and type of their gills, the number and situation of their 

 nepliridia, the nature of their septal pouches, statocysts, and stato- 

 liths. The systematic position of the species may be stated thus: 

 A. glacialis presents no affinity with A. clajjaredii and is so slightly 

 related to A. assimilis that the relationship may be neglected; it 

 presents externally some resemblance to A. cristata, having the same 

 number of segments and gills, but its internal organs are very like 

 those of A. marina and in the form of its prostomium and the character 

 of its gills it is more like A. marina than any other species. A. 

 glacialis is related to A. cristata and A. marina, but much more closely 

 to the latter than to the former. 



THE DIFFERENT REGIONS OF THE AMERICAN SEABOARD AND THEIR 



SPECIES OF ARENICOLA. 



1. East coast of North America: 



Arenicola viarinahas been taken at numerous stations on this coast from Rigolet, 

 Labrador, to Noank, Connecticut. The southern limit of this species is prob- 

 ably about 40° N. 



Arenicola cristata extends from Woods Hole southward to Florida, and is also 

 known from Bermuda. 



2. Gulf of Mexico, West Indies, Carribbean Sea: 



Arenicola cristata is the only species known from this region; it is recorded 

 from Florida, Jamaica, Santa Cruz, and Cura(;^ao. 



3. East coast of South America as far south as lat. 51° S.: 



There are no records whatever from this portion of the coast. 



4. North coast of North America: 



Arenicola glacialis is recorded from Port Barrow, Alaska. This is the only 

 record of Arenicola from the arctic shores of America.^ 



5. West coast of North and South America as far south as lat. 51° S.: 



Arenicola cla2xiredii is recorded from several stations on this coast, namely, the 

 Aleutian Islands (Amchitka, Atka, Unalaska), Vancouver Island, San Juan 

 Island, Puget Sound, California, Coquimbo, and Puerto Montt (Chile). 



Arenicola cristata is now recorded from two stations on the Californian coast, 

 namely, Monterey Bay and San Pedro. 



6. Southern extremity of South America, south of lat. 51° S.: 



Arenicola assimilis and the variety affinis are the only forms known from this 

 region. A. assimilis is known from the Strait of Magellan, the Beagle Chan- 

 nel, and South Georgia. The variety affinis is recorded from the Strait of 

 Magellan, the Beagle Channel, and the Falkland Islands. 



"■Arenicola is recorded from Greenland, which I have not included as American. 

 All the known specimens from Greenland are A. marina. 



