358 
BULLETIN OF THE BUREAU OF FISHERIES 
As in the case of Palaemonetes carolinus, there are indications that P. vulgaris 
migrates into deeper water during the colder months; for all the specimens, with the 
exception of two, collected during our cruises were taken during the colder months. 
The two exceptions were ovigerous and were found at the shallow area 0 (8 
meters) during the July cruise, 1920. The occurrence of these egg-bearing specimens 
in July and the finding of the larvae of this form only during the July and August 
cruises of 1920 show that the breeding season was during the summer months. On 
those two cruises the larvae were found at areas covering practically the whole bay 
(U, V, W, Q, A, D, H', and R'). 
Crago septemspinosus , which has been known under the names Crangon septems- 
pinosus Say and C. vulgaris Smith, was by far the most common shrimp in our collec- 
tions during the years 1915, 1916, 1920, 1921, and 1922. It is known to frequent 
deeper water than Palaemonetes vulgaris (Verrill, 1874, p. 45) and is called the “sand ” 
or “grey shrimp” because it is common on sandy bottoms. In the Chesapeake it 
was collected from all the areas visited with the exception of U, which is not far from 
Baltimore. Probably it is more abundant in the lower two-thirds of the bay, al- 
though like P. carolinus it has been found at St. George Island and Blakistone Island 
10 and 25 miles, respectively, up the Potomac River, and in Island Creek, which is 
about 10 miles upstream from the mouth of the Choptank River. 
Ovigerous specimens of Crago septemspinosus were taken at all seasons of the year; 
but they were caught most abundantly during the fall, winter, and spring cruises. 
The summer cruises brought to light few ovigerous specimens. Juvenile individuals 
were reported by Schmitt from our July, August, October, December, 1920, and our 
March, 1921, cruises. At Woods Hole, Mass., Bumpus (1898) found Crangon breed- 
ing during March, and Thompson (1899) during September, while Fish (1925, p. 156) 
reports “great numbers of adult females bearing eggs in Naragansett Bay” in the 
month of May, 1922. Bumpus’ statement that “ * * * it would be interesting to 
learn when this species is not pregnant,” is well put. 
Peneus setijera and P . brasiliensis, the two large shrimps of markets, have been 
collected from the lower bay and from such rivers as the Rappahannock, but in small 
numbers. Evidently they are more at home farther south along the coast. 
All the rest of the shrimps collected were found outside only or, in a few cases, in 
the lower part of the bay and in small numbers. The localities where they have been 
taken are indicated in the lists given above. Three species, Hippolyte acuminata, 
Latrutes jucorum, and Palaemon tenuicornis, were collected at the surface only. 
The Galatheidea are represented in our collection by the single species Munida 
iris A. M. Edw. Over 1,400 specimens have been collected off Chesapeake Bay by 
various collectors and placed in the United States National Museum. The records 
show that these were taken at depths varying from 78 to 328 meters. Evidently it is 
a form of the deeper and more saline waters. It was never taken inside of the bay 
during our cruises; but in August, 1920, when we visited several stations located along 
a line extending from the mouth out to the 100-fathom line, 5 specimens were col- 
lected — 2 probably at 78 meters and 3 probably at 216 meters (I say “probably” be- 
cause a nonclosing net was used.) The surface and bottom salinities at the 78-meter 
station, which was only ashort distance from the mouth, were 29.91 and 33.29per mille. 
The temperatures were 24.1° C. and 8.5° C. This species must be very abundant in 
places, for as many as 250 specimens have been collected at a single dredging station. 
A rare species of the family Porcellanidae, namely, Euceramus praelongus Stimp- 
son, was collected on three occasions: During October, 1915, off the Inner Middle 
