BIOLOGICAL STUDY OF CHESAPEAKE BAY WATERS 
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42. There are only two abundant annelids, Nereis limbata and Polydora ligni, 
which are found widely distributed in the offshore waters of the bay. They have 
been collected during all seasons of the year. These species and such others as 
Goniada oculata, Pectiniaria gouldii, and Paranaitis speciosa are evidently able to live 
in waters of widely differing salinities and temperatures. 
43. Four species, Streblospio benedicti, Scolecolepis viridis, Prinospio plumosa, 
and Pectinaria gouldii, have been dredged only from that part of the bay extending 
from the mouth of the Potomac River to near the mouth of the Patapsco River, and 
consequently from waters of low salinities. 
44. The following were found only in the lower half of Chesapeake Bay, where 
the salinities are much higher: Lepidonotus squamatus, Harmothoe aculeata, Nereis 
dumerilii, while Myriana cirrata, Glycera americana, Maldane elongata, Praxiothea 
torquata, Eupomatus dianthus, Terebella ornata, and Loimia turgida were only dis- 
covered near the mouth of the bay. 
45. While there is no proof from the data at hand that the degree of salinity is 
a factor governing the distribution of the annelids in Chesapeake Bay, yet there are 
indications that such is the case. However, it is certainly true that the character of 
the bottom and the occurrence of the proper kind of food are important factors. 
46. One species representing the Hirudinea was found in the offshore waters of 
the bay. It was the fish-leech, Piscicola punctata. 
47. Of the 64 species of copepods collected, only two — Acartia clausii and A. 
longiremis — have been found sufficiently abundant in the bay to be of economic 
importance. These were distributed over the whole bay from the region of Baltimore 
to the mouth and were caught during all the cruises throughout the year. Ten 
species, including the two mentioned, must have been able to accommodate themselves 
to a large range of salinities, since they were collected, in good condition, all over the 
bay, in addition to the ocean. Both of these species have been found breeding in 
Chesapeake Bay. 
48. Two species of barnacles, Balanus improvisus and B. eburneus, have been 
collected in the deeper waters of the lower part of Chesapeake Bay (from the mouth 
of the Potomac River to the mouth of the bay). However, along the shores of the 
bay there is at least one unidentified species which is found frequently on piles as far 
north as the mouth of the Patapsco River. 
49. The collection of amphipods, consisting of nine species, represents merely the 
catch made during the cruise of May, 1920. All of the specimens came from the 
shallower areas and from water that did not exceed 21.00 per mille in salinity. 
50. Information concerning the isopods of Chesapeake Bay is limited to material 
collected on the cruise of May, 1920. Five species were found. 
51. The most abundant schizopod caught during our cruises was Neomysis 
americana (formerly known as My sis americana). Large numbers of surface to wings 
show that this species does not ordinarily frequent the surface waters in the daytime. 
Specimens were captured during all the cruises taken in the year 1920 (January, 
March, May, July, August, October, and December). Some breeding individuals 
were found on almost all of the cruises. The records show that this form can live in 
waters of a wide range of salinities and temperatures. 
52. One species of stomatopod, Chloridella empusa (called Squilla empusa by the 
earlier systematists), has been caught in the bay. This common, shore-dwelling 
marine form has been found distributed from near the mouth of the bay to a region 
1988—30 7 
