KEW SPECIES OF BRANCHINECTA — ^LYNCH 559 



a length of 1,500/*. Near the apex of the endopodite the last five 

 or six setae become shorter and stouter, the fine delicate hairlets 

 that border them become shorter and more bristlelike, and the setae 

 transform rather abruptly to the hooked spines of the internal border 

 of the endopodite. 



A typical spine of the distal half of the median border of an 

 endopodite is depicted in pi. 79, fig. 3. The tip is turned dorsally 

 to form a hook with an arrowhead tip. On the dorsoposterior side 

 of the spine a triangular area, outlined by a row of denticles about 

 30/x in length, extends from the hook about three-fourths the length 

 of the spine toward its base. Inside this triangular are^ there is a 

 dense aggregation of slightly shorter denticles, about 22/* in length, 

 arranged in poorly defined oblique rows. 



The number of these hooked spines varies somewhat in difi'erent 

 appendages and also from individual to individual. Starting at the 

 distal end of the endopodite of an appendage from the middle of the 

 series there may, or may not, be a heavy, straight-tipped, denticulate 

 spine. Next are six to nine denticulate spines with strongly hooked 

 tips, of the type shown in pi. 79, fig. 3. The proximal 12 or 13 spines 

 become progressively straighter at the tip and slenderer ; the denticles 

 become more closely set and delicate, and the area of denticles ex- 

 tends more completely aroimd the spines until the last few (two to 

 five) become slender, straight-tipped setae whose entire surface in the 

 distal two-thirds is covered with fine hairs (pi. 80, fig. 2). In ap- 

 pendage 11 none of the denticidate spines has a strongly hooked tip. 



The five endites are bordered by long setae of the type just de- 

 scribed (pi. 80, fig. 2). Endites 1 and 2 are swollen and are nearly 

 1 mm in anteroposterior diameter. They bear a row of stout setae, 

 which arise near the edge on the posterior side; endite 1 bears two 

 setae near the anterior border, accompanied each by a small spur; 

 endite 2 bears one such setae and spur. Endites 3 to 5 are broadly 

 swollen, bearing 5 to 12 setae on the anterior border and 3 to 5 on the 

 posterior border. Endites 3 and 4 bear each a long hairless seta in 

 the center of the median surface. 



The anterior and posterior surfaces of the tip and median border 

 of the endopodite and of the border of all the endites are covered 

 with fine, short, bristlelike hairs about 15/* in length, arranged in 

 short comblike rows (pi. 79, figs. 1, 3; pi. 80, fig. 2). These fine 

 bristles, the tips of which are directed medially and dorsally, thus 

 form a broad band on both sides of the median borders of the ap- 

 pendages. The lateral walls of the ventral thoracic groove are also 

 fringed with thickly set stiff hairs about 50/* in length (pi. 79, figs. 1, 



The penes are eversible and retractile. In most of the specimens 

 they are wholly retracted or only partially protruded. Plate 80, 



