164 PROCEEDINGS OF THE NATIONAL MUSEUM vol. in 



and the warm-temperate faunas to the south and is thus relatively- 

 rich in species of both subfamilies. Some of the species (e.g., in 

 Neohaustorius, Parahaustorius , and Acanthohaustorius) appear to be 

 endemic to the Cape Cod region although further careful collecting in 

 selected habitats undoubtedly wUl increase the geographical range, 

 particularly southward, in these instances. Such endemicity, whether 

 real or apparent, is known in other invertebrate groups (e.g., cuma- 

 ceans, mysids). The wide range of inshore water temperatures in the 

 Cape Cod region, both geographically and bathymetrically, coupled 

 with the absence of extreme or prolonged winter lows and excessive 

 summer highs, enhances the suitability of the habitat and thus con- 

 tributes significantly to the richness and diversity of its haustoriid 

 fauna. In this respect the region compares favorably with the south- 

 ern British Isles in the eastern Atlantic and with southern California 

 in the eastern Pacific. 



New England haustoriids are essentially intertidal and shallow-water 

 crustaceans. On the outer, surf-exposed sand beaches, especially 

 where sand remains damp at low water through seepage or fresh- 

 water outflows, are found the large Haustorius canadensis, the smaller 

 Amphiporeia virginiana, and minute Bathyporeia quoddyensis. Along 

 semiprotected shores, H. canadensis occurs at midwater levels, 

 whereas the somewhat smaller Parahaustorius longimerus and Acantho- 

 havstorius millsi are dominant near low-water level. Here also, 

 particularly near the mouths of sandy estuaries, ProtohaustoriiLs 

 deichmannae'is often abundant. Neohaustorius hiarticulatus is restricted 

 to sandy banks of salt marsh creeks. Subtidally and oflFshore, 

 especially over the southern Georges Bank region and Long Island 

 Sound, occur the larger and more powerful species, such as Para- 

 haustorius holmesi and P. attenuatus, others of intermediate size, 

 such as Protohaustorius wigleyi, Pseudolmustorius borealis, and Acan- 

 thohaustorius shoemakeri. Pseudohaustorius caroliniensis is an estu- 

 arine form of muddy sand and seepage beds from Buzzards Bay 

 southward. 



From Casco Bay northward along the outer coasts of Maine and 

 Nova Scotia, Haustorius canadensis, Acanthohaustorius millsi, and 

 Protohaustorius deichmannae quickly disappear, but the former re- 

 appears along the dune beaches in the southwestern Gulf of St. 

 Lawrence and Cape Breton Island (Bousfield, 1964b). Similar 

 habitats of the colder intervening region are populated largely by 

 the isopod Chiridothea caeca, whereas the low-water and subtidal 

 levels are dominated by Amphiporeia lawrenciana, the minute 

 Bathyporeia quoddyensis, and the large lysianassid Tmetonyx nobilis. 

 Acanthohaustorius spinosus and Bathyporeia quoddyensis, normally 

 subtidal, appear regularly at low-water level of the few sand beaches 



