354 REPORT OP COMMISSIONER OF FISH AND FISHERIES. 



schooner 'Frederick Gerriug, jr.', Oapt. Edwin Morris. Dr. Packard's 

 locality is "Sloop Harbor, Kynetarbuck Bay [Labrador], seven fathoms 

 on a sandy bottom." Whiteaves records the species from Orphan Bank, 

 Gulf of Saint Lawrence. Lockiugton's specimens were collected on the 

 " west coast of Alaska, IST. of Behring's Strait, by W. J. Fisher, natu- 

 ralist of the U. S. S. Tuscarora, Deep-Sea Sounding Expedition." 

 Owen's locality is " the Arctic Seas." 



Erichsonia Dana. 



Urichsonia Dana, Am. Jour. Sci., II, vol. viii, p. 427, 1849. 



AntennaB six-jointed, the terminal or flagellar segment not articulated, 

 clavate; palpus of the maxLllij)eds four-jointed; legs aU nearly aUke, 

 prehensile or sub-prehensUe ; pleon with its segments consohdated into a 

 single piece. 



This genus is represented within our limits by two weU-marked spe- 

 cies, which further agree in the following characters : The head is quad- 

 rate, with the eyes lateral. The antennulae are short, not surpassing the 

 third segment of the antennae. The antenme are well developed, more 

 than half as long as the body, with a very short basal segment articu- 

 lated with little or no motion to the second segment, which is two or 

 three times as long as, and of greater diameter than the first. It is, as 

 usual in the family, incised at its distal end on the under siu"face. The 

 next three segments are nearly cylindrical. The last or flagellar seg- 

 ment is the longest, and is shghtly clavate. 



The legs are all terminated by a prehensile or sub-prehensUe hand, the 

 dactylus being capable of considerable or complete flexion on the more 

 or less swollen iwopodus. This flexion is most complete in the first pair. 

 The first two pah's of legs arise near the anterior margin of the segments 

 to which they belong. The place of attachment to the segment moves 

 gradually backward in the following pahs until the last two pairs arise 

 near the posterior margin of the last two segments. The epimera are 

 more or less evident from above, at least in the last two segments. 



The pleon constitutes about one-third the length of the body, and is 

 consolidated into a single piece; it bears a more or less evident tooth on 

 each side near the base, and is dilated and obtusely triangular at the 

 apex. The basal i)late of the operculum is oblique at the anterior end 

 and abruptly narrowed posteriorly, where it bears a densely plumose 

 bristle, as in Idotea ; the terminal plate is triangular. The stylet on the 

 second pair of pleopods in the males is well developed, surpassing the 

 cilia ; it is minutely denticulated or sijiuulose near the end and very 

 acute. 



The two species found on our coast have but a slight external resem- 

 blance to each other, and may be distinguished at a glance, as will be 

 seen from the specific descriptions, and from the figures (pi. VI, fig. 36, 

 and pi. VII, fig. 38). The long, clavate terminal segment of the antennaa 



