72 REPORT OF COMMISSIONER OF FiSH AND FISHERIES. [366] 
Bryozoa and Ascidians. 
Page. Page, 
Molgula Manhattensis...-.. 361 | Bugula turrita.........--. 361 
Escharella variabilis........ 361 
RADIATA. 
Echinoderms. 
Page. Page. 
Thyone Briareus........... 362 | Echinarachnias parma. .... 362 
Caudina arenata......-.... 362 | Asterias arenicola......... 363 
Leptosynapta Girardii...... 361 | Ophiura olivacea.......... 363 
L. roseola ......--.--++---- 362 
Polyps. 
Page. Page 
Halocampa producta ....... 363 | Sagartia leucolena ........ 363 
Sagartia modesta.......-.. 363 | Paractis rapiformis........ 363 
Il. 3.—FAUNA OF THE MUDDY SHORES OF THE BAYS AND SOUNDS. 
The muddy shores in this region grade almost insensibly into the sandy 
shores; and shores thatare entirely of mud, without any admixture of fine 
sand, rarely occur except in the estuaries and lagoons. Therefore we 
find, as might have been anticipated, that it is difficult to draw a very 
definite line between the animals living upon the sandy shores ard those 
living upon the muddy shores and flats. Many of the species seem, also, 
to be equally at home, whetber living in mud or sand, and many others 
prefer a mixture, although capable of living in either. But if we were 
to compare the animals living in pure sand with those living in clear 
mud, the two lists would be quite different, although a considerable 
number would be common to both lists. Moreover, the eel-grass grows 
in considerable quantities both upon sandy and muddy shores, in cer- 
tain localities, and a large number of species which inhabit the eel-grass 
will, therefore, be found in both lists. 
In discussing the species found on sandy shores, in the preceding 
pages, references have constantly been made to other stations inhabited 
by many of the species, and especially in the case of those that are com- 
mon to the sandy and muddy shores. Therefore it will not be necessary 
to repeat the facts in this connection, but the species will be enumerated 
in the list at the end of this section. 
A considerable number of species have their place in this list chiefly 
because they occur on beds of oysters planted on muddy shores, at and 
just below low-water mark. Without these artificial stations some of 
them would hardly be found on such shores, or at least but rarely. It 
is evident that the shells of oysters, when in large quantities, supply, to 
