70 



BULLETIN OF THE BUREAU OF FISHERIES. 



We have accordingly adopted the following classification of bottoms in the ensu- 

 ing discussion of habitats: 



A. "Sand," including bottoms recorded as pure sand, or sand and shells. Bot- 

 toms containing stones, gravel, or mud are excluded. 



B. "Gravel and stones," including records which list either of these ingredients 

 singly or in combination with one another or with sand. No bottoms containing mud 

 are here included. 



C. "Mud," including bottoms recorded as of mud, muddy sand, or sandy mud. 

 Bottoms are here included in which shells are listed, but not those containing gravel or 

 stones. 



Certain combinations (e. g., gravel and mud) are excluded from this classification, 

 and records from such stations are not included in the present list. Such cases are, 

 however, relatively very few. 



VI. Species taken at one-fourth (43) or more of the stations dredged on sandy bottoms. 



Porifera: 



Cliona celata (49). 

 Hydrozoa: 



Hydractinia echinata (46). 

 Bryozoa: 



Crisia eburnea (74). 



Bugula turrita (107). 



Schizoporella unicornis (63). 



Smittia trispinosa nitida (44). 

 Asteroidea: 



Asterias fbrbesi (71). 



Asterias vulgaris (56). 

 Echinoidea: 



Arbacia punctulata (48). 



Echinarachnius parma (101). 

 Annulata: 



Harmothoe imbricata (72). 



Lepidonotus squamatus (54). 



Nereis pelagica (72). 



Diopatra cuprea (72). 



Hydroides dianthus (61). 

 Cirripedia: 



Balanus eburneus (51). 

 Decapoda: 



Crago septemspinosus (80). 



Pagurus longicarpus (101). 



Pagurus annulipes (59). 



Libinia emarginata (62). 



Decapoda — Continued. 



Cancer irroratus (92). 



Ovalipes ocellatus (43). 

 PElecypoda : 



Anomia simplex (97). 



Pecten gibbus borealis (52). 



Mytilus edulis (113). 



Area transversa (105). 



Nucula proxima (62). 



Venericardia borealis (49). 



Astarte undata (44). 



Astarte castanea (59). 



Crassinella mactracea (72). 



Cardium pinnulatum (83). 



Callocardia morrhuana (78). 



Tellina tenera (96). 



Ensis directus (84). 



Spisula solidissima (109). 



Clidiophora gouldiana (88). 



Corbula contracta (46). 

 Gastropoda: 



Tritia trivittata (142). 



Anachis avara (95). 



Astyris lunata (94). 



Urosalpinx cinereus (46). 



Crepidula fornicata (124). 



Crepidula plana (in). 



Polynices heros (80). 



Polynices triseriata (51). 



Of the foregoing 46 species all but 2 appear in one or both of the lists for Vine- 

 yard Sound. On the other hand, 8 of the species do not appear in either list for Buzzards 

 Bay, and 14 do not appear in the Fish Hawk list for Buzzards Bay. These facts follow 

 directly, of course, from the well-known differences of these two bodies of water in respect 

 to the character of their bottoms. 



