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BULLETIN OF THE BUREAU OF FISHERIES 
The lists just given include those species which were found in the bay, while 
the list which follows contains the species which have been collected outside, not far 
from the mouth of the bay. 
Outside only . — Shrimps: Pandalus leptocerus Smith, Caridion gordoni (Bate), Hippolyte acum- 
inata Dana, Latreutes fucorum (Fabr.), Spirontocaris pusiola (Krpyer), Spriontocaris polaris (Sabine), 
Palaemon tenuicornis Say, Pontophilus brevirostris Smith. Galatlieids: Munida iris A. M. Edw. 
Hermit Crabs: Calapagurus gracilis Smith, C. sharreri M. Edw., Pagurus acadianus Benedict, P. 
kroyeri (Stimp.), P. politus (Smith). Hippas: Emerita talpoidia (Say). Crabs: Homolo barbata 
(Fabr.), Bathynecies superba Costa, Portunus ( achelous ) spinimanus (Latr.), Portunus sayi (Gibbes), 
Cancer borealis Stimp., Sesarma ( Sesarma ) reticulatum (Say), Collodes robustus Smith, Euprognatha 
rastellifera aclita A. M. E. (probably), E. rastellifera marthae Rathbun, Hyas coarctatus Leach. 
A few specimens were collected both outside and in the lower bay. 
Outside and lower bay . — Shrimps: Penaeus setifera (L.), P. brasiliensis (Latr.), Parapenaeus 
constrictus (St.), Crago septemspinosus (Say). Hermit Crabs: Pagurus longicarpus Say, Pagurus 
pollicaris Say. Crabs: Ovalipes ocellatus (Herbst), Cancer irroratus Say, Neopanope texana sayi 
(Smith), Panopeus herbstii Edw. (probably), Sesarma ( Holometopus ) cinereum (Bose.), Ocypoda 
albicans Bose., Uca pugilator (Bose.), Uca pugnax (Smith), and Libinia emarginata Leach. 
The localities for two species, Ilepatus epheliiicus (L.) and Callinectes ornatus 
Ordway, have not been determined. 
A study of the lists just given shows that only 1 species was found exclusively 
in the upper bay (its distribution may be more extensive) ; that 1 1 were common to 
both the upper and lower bay; that 27 were found exclusively in the lower bay; that 
25 were taken only outside of the bay; and that the localities of 2 were not determined. 
This makes a total of 66 species. 
The lists below are designed to show the probable distribution of the decapods 
(for which we have sufficient data) in the offshore waters of Chesapeake Bay; that 
is, exclusive of the shallow water shore forms and the forms in rivers and creeks. 
The conclusions arrived at are based on our systematic collections during cruises 
covering a considerable period, checked to some extent by data from shore, river, 
and creek collections which, however, have been of an unsystematic nature. 
Our data do not afford evidence to show that there are any species of decapods 
which are distributed exclusively in the offshore waters of the upper bay; that is, 
above the mouth of the Potomac River. 
Decapods of the offshore waters of upper and lower bay.- — Palaemonetes carolinus Stimpson, P. 
vulgaris (Say), Crago septemspinosus (Say), Pagurus longicarpus Say, Callinectes sapidus Rathbun, 
Rilhropanopeus harrisii (Gould), Eurypanopeus depressus (Smith), Hexapanopeus angustifrons 
(Benedict and Rathbun), and Sesarma ( Holometopus ) cinereum (Bose.). 
Decapods of the offshore waters of lower bay only. — Peneus setifera (L), Trachypeneus constrictus 
(Stimpson), Crago packardi (Kingsley), Euceramus praelongus Stimpson, Pagurus pollicaris Say, 
Ovalipes ocellatus (Herbst), Portunus gibbesii (Stimp.), Cancer irroratus Say, Neopanope texana sayi 
(Smith), Panopeus herbstii Edw., and Libinia emarginata Leach. 
Almost all of the 18 species of shrimps or shrimplike forms found in Chesapeake 
Bay and the immediate vicinity have been found in such small numbers that no more 
information concerning them can be given than that which appears above. Three 
species, however, Palaemonetes carolinus, Palaemonetes vulgaris, and Crago septemspi- 
nosus, deserve more attention, since they have been collected more often in Chesapeake 
Bay and since we have more data concerning the environmental conditions under 
which they live. 
Palaemonetes carolinus, which is known to occur all along the eastern coast of 
the United States (Kingsley, 1899), seems to be a shallow-water form, judging from 
