STUDIES IN MARINE ECOLOGY. 211 



Part I. is from collections made off the Bay opening of Northwest 

 Gutter about 75 yards directly west of the corner of the channel 

 made by the shoulder of Uncatena Island. Part II. is from the 

 passage in Woods Hole and the third part is from the opening of 

 Lackey's Bay into Vineyard Sound. The latter is influenced by 

 the current carrying water from the extensive submerged vegeta- 

 tion of this region. Part IV. is from the mid-mouth of Gansett 

 Bay. The surface water here also shows the effect of proximity 

 to vegetation. The depths are those given in the U. S. Coast and 

 Geodetic Survey charts. The last two divisions are given for 

 comparison only and will not be considered in discussing open 

 water conditions since they are obviously atypical. 



The invertebrate animals to be found near the surface in such 

 locations are largely plankton. A typical collection taken with 

 miller's bolting cloth net from a Bay tide in Woods Hole at 

 10:00 A.M., August 8, 1917, is shown in List 1. The collection 

 was studied the afternoon after it was taken by the class in 

 Invertebrate Zoology of the Marine Biological Laboratory with 

 the assistance of seven instructors. The list is based on the 

 findings of approximately sixty people in a two hours search. 



List i. Showing the More Conspicuous Animals Taken in One 

 Towing in the Hole. 



Animals. Number Found. Animals. Number Found- 



Protozoa Bryozoa 



Ceratium 8 Cyphonautes 5 



CCELENTERATA CRUSTACEA 



Actinula of Tubularia 2 Nauplius 3 



Hydromedusge 12 Zcea 5 



Nemertini Mysis 4 



Pilidium of Cerebratulus 1 Megalops 5 



Ch/etognatha Copepoda <x 



Sagitta 2 Cypris larvae of Balanus 1 



Echinoderma Mollusca 



Bipinnaria 12 Lamellibranch veligers. ....... 4 



Brachiolaria 5 Gasteropod veliger oc 



Pluteus 2 Chordata 



Annelida Appendicularia 14 



Dinophilus 5 Botryllus tadpoles 1 



Trochophores 2 



b. Wharf Piling Association. — The animals in this association, 

 whether free living, attached, or living among attached forms, 

 are more abundant at the outer end of the piers where the water 



