96 KEITISH TUXICATA. 



The branchial sac (PL XVII, fig. 6) extends a little 

 below, and is rather narrower than, the visceral mass, 

 which passes beyond its boundary in the dorsal region ; 

 it is minutely plicated. The primary vessels are rather 

 distant and regular, and the stomata of the secondary 

 vessels rather wide, somewhat irregular and short, with 

 the extremities usually pointed. The longitudinal bars 

 are rather stout, with the papillae unusually short, 

 broad, and rounded ; they are alternately large and 

 small, the latter being 011 the bars between those at the 

 intersections of the meshes ; and all have a hispid 

 appearance, probably caused by the remains of cilia. 

 The papillary membrane is distinct but limited in 

 extent. The oral lamina (PL XIX, fig. 5) is well 

 developed, and is strongly and closely ribbed on the 

 right side, less strongly on the left; the margin is 

 minutely pectinated, there being usually three or four 

 small points on the membrane between those of the 

 ribs which are larger and stronger than the rest. The 

 lamina is smooth and little developed below the mouth. 

 On the left side of the oral orifice the row of tentacular 

 points is well defined ; it consists of about thirty large, 

 triangular, sharp-pointed, leaf-like processes. The 

 branchial tubercle (PL XX, fig. 6) is small, and is a 

 simple loop open in front. The tentacular filaments 

 of the incurrent tube are about forty in number ; they 

 are of moderate length and rather slender, closely 

 arranged in a single row and attached by the base for 

 some little distance upwards. As a few of the smaller 

 ones are more slightly attached than the rest, there is 

 somewhat the appearance of an interrupted second or 

 upper row of short filaments. 



The ovary is a rather slender, branched organ, 

 ramifying over 'the upper portion of the left side of the 

 intestinal loop. The oviduct is seen as usual on the 

 right side following the sinuosities of the intestine ; it 

 is a wide tube, the rounded proximal extremity of 

 which, penetrating the intestinal loop, is seen at the 

 left side where it becomes connected with the ovary. 



