326 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



by Kroyor in his specimens of 31. Fahricii. The legs in the small speci- 

 men figured are considerably shorter than in larger specimens obtained 

 in 1878, aud the flagelliim of the antennulee consists in the small speci- 

 mens of a single segment, or with traces of subdivision into two, while 

 in the large specimens it is four-jointed, with a rudimentary terminal 

 segment. 



The body is in the female elongate oval, tapering posteriorly, and 

 broadest at the third thoracic segment, where the breadth is equal to 

 about half the length. The males are more slender, and are not dilated 

 behind the head. The head forms about one-fifth of the total length, and 

 is nearly twice as broad as long. Its anterior portion between the bases 

 of the antennulae aud antennte is comparatively narrow on its upper 

 surface, and is rounded or obtusely angled in front. Behind the bases 

 of the antennulfB it is suddenly much dOated at the sides, and a httle be- 

 hind the dilation are the prominent, strongly convex and laterally pro- 

 jecting eyes, immediately behind which the head contracts suddenly in 

 width, and is then slightly rounded behind. The antennulte arise in a 

 deep sinus on the anterolateral region of the head. They consist of a 

 four-jointed peduncle followed by a four-jointed flagellum of about the 

 same length as the peduncle. The basal antennular segment is stout, 

 and subtrigonal in form ; the second is more slender and cylindrical, 

 while the third and fourth are subequal, quite short and small, together 

 not over half as long as the second segment, and should perhaps rather 

 be regarded as flagellar segments. The four flagellar segments are of a 

 little less diameter than the last two peduncular segments, and are long 

 and cylintMcal, the fourth being tipped with a rudimentary segment 

 bearing two strong terminal setae. The antennae are much larger and 

 stouter than the antennulae and are about two or three times as long as 

 the body. They are composed of a five-jointed peduncle aud a slender 

 multiarticulate flageUum. They arise nearly in front of the autennidae 

 and their first three segments are short and stout, not longer taken to- 

 gether than the first two antennular segments. The fourth segment of 

 tlie antennae is only about half the diameter of the first three segments, 

 but is greatly elongated, nearly or quite equaling in length the head 

 and thorax taken together, and is cylindrical, and provided with a 

 few short setae, especially at the -tip. The fifth, or last peduncular, 

 segment is slightly more slender and elongated than the fourth, and is 

 followed by a slender tapering flagellum composed of about seventy-five 

 segments, or, perhaps, in perfect specimens, of a greater number. The 

 maxillipeds are large and broad, as required by the large head, and are 

 furnished with a five-jointed j)alpus, with the basal segment short, the 

 second and third flattened and expanded internally, where they are also 

 ciliated; the fourth narrow; the fifth short, and both provided with scat- 

 tered setae, especially toward the tip. 



The first thoracic segment is a little shorter than the second, which is 

 about equal in length to the third and the fourth ; the last three seg- 



