15G [ASSEMBLT 



PaKAXIOTHEA LATEN8 U, Sp. 

 LATK (VI), X, FIGS. 63-66. 



Frontal membrane (figs. 62, 63) forming one-half tho length of 

 the first segment ; anterior margin slightly refiexed, lobed or scol- 

 loped by shallow incisions, wliicli are continued as impressed lines 

 for some distance, on both the outer and inner surface of the mem- 

 brane ; superior emargination broad but shallow. 



First segment a little longer than the second, about equal to the 

 sixth; second, third and fourth equal; fifth a little shorter; seg- 

 ments six to ten grow progressively longer, but so gradually that 

 the change is hardly perceptible; eleven to thirteen also gain in 

 length progressively, but rapidly, the thirteenth having double the 

 length of the tenth ; fourteenth, fifteenth and sixteenth about equal 

 to the tenth ; seventeenth and eighteenth short, equal, together 

 about equal to the sixteenth, a trifle longer than the anal. 



Diameter of first segment a little less than that of the second ; 

 uniform from second to tenth inclusive ; falling off abont one-third at 

 the eleventh, after which the decrease is very slight. 



One ante-anal nude segment (fig. 64) with thickened, rounded, 

 posterior margin, forming a collar around the front end of the anal 

 segment. 



Anal segment with numerous, short, unequal cirri or digitations, 

 quite similar to Clymenella tor'cpiata Yerrill, or Praxilla elongata 

 Webster. 



The dorsal (capillary) setse (fig. 65) are long, delicate, numerous, 

 with a single thin margin. The uncini hav^e the same form on all 

 the segments (fig. QQ) ; they have five sharp terminal teeth, of which 

 three are small and equal ; the fourth longer and larger than the 

 third ; the fifth double the size of the fourth. On the first three 

 segments there are from fifteen to twenty uncini in each series; 

 after the third, from twenty to twenty-five, except on a few of the 

 posterior segments, where there is a smaller number. The first five 

 segments have the setie on the middle line, and a deeply impressed 

 ventral line connects the series of uncini on each segment. After 

 the fifth segment the setre are near the posterior end, and after the 

 tenth the dorsal rami {tori uncinigeri) are quite large, making the 

 segments somewhat club-shaped. 



Number of segments, 19; of these 17 are setigerous; one ante- 

 anal, nude ; one anal. 



Color (in alcohol) yellowish-white ; on one specimen broad bands 

 of umber-brown cross tho ventral surface, dividing at the uncini, 

 giving a narrow band on each side of each series of uncini after 

 the fifth. 



At Great Egg Harbor we obtained two specimens, both of which 

 had lost their posterior segments. The longest has fifteen segments, 

 with a length of 65™'"; greatest diameter, 3™°^. Tiie description 

 was completed from a single perfect specimen, collected by Mr. 

 James E. Benedict of South Norwalk, Conn., during the same 

 summer. 



