Further Observations on Koeneuia. 4]^ 7 



the second segmeiit consist of two pairs of larg-e conical papillae, 

 eacli terminating- in a plumulose curvecl seta aud foiir pairs of small 

 papillae. These papillae are obliquely truncated and on the slantin^ 

 end, but not at the tip, is a plumulose seta. Underneath these 

 papillae and arising- from the same seg-ment is a pair of triangulär 

 plates. A section of these plates would likewise appear triang-ular 

 with the inner edg-e slig-htly concave and irregulär. The appendages 

 are armed with flve pairs of plumulose setae. The large and thick 

 pair of appendages of the third segment present a broad and ex- 

 tended anterior surface and a very short posterior surface. These 

 are armed each with flve setae on or near their tips while a pair 

 of small setae arise high up at the point where the appendages 

 merge into the body wall. The rough edges of the posterior pair 

 of appendages of the second segment and those of the third segment 

 appear to possess partial perforations near their margin. There is 

 a row of ten setae which arise on the ridge of tlie second segment 

 from wdiich the papillae project; anterior to this row, there is another 

 one of ouly four setae. 



In the female the appendages themselves are easil}^ understood. 



The second segment becomes prolonged on the ventral side posteriorly 



into a triangulär Aap. This unpaired appendage possesses six rows 



of hairs, the rows themselves being arranged in pairs. Both of the 



upperraost row" of four setae run in such a way as to form the 



sides of an inverted V. The middle rows consist of four setae each, 



which converge as they run down forming a V, minus a seta for 



the apex. The remaining row^s, of three hairs each, follow fairly 



closely the edge of the appendage. This makes in all for this organ 



i eleven pairs of plumulose setae, wdiereas in my formed paper I 



j figured only nine pairs, yet Dr. Hansen says "the figure of the 



I anterior genital lobe in the female is not correct, the essential fault 



I is that too numerous setae have been drawn". The pairs of appen- 

 ' dages for the third segment are very mach like the corresponding 

 ' ones in the male. They possess, projecting from their under surface, 



two pairs of setae somewhat larger than the other setae belonging 

 to these appendages. From their sides, near where the appendages 



■ j merge into the body-wall, there is, just as in the male, a pair of 



;| setae, one for either side. 



il Just the opposite to the definite condition found in the chaeto- 



[ taxy of the reproductive appendages is the condition observed 



I I on the flagellum of Koenenia. This organ is liable to injury and 



28* 



