80 



PROCEEDINGS OP THE NATIONAL MUSEUM. 



VOL, 46. 



KomnL 



FlQ. 5.— RiCTULAEIA 



SPLENDIDA. Head 



OF FEMALE. 



from combs to spines is very gradual. I have divided the 136 combs 



and spines into 120 combs and 16 spines, though tliis might be sliifted 



one or two either wa3^ In one specimen the apparent total of combs 



and spines is 138. The combs attain a maximum height of 72 ri in the 



neck region. The last spine is about 1.7 mm. from 



the posterior end of the body. The anus is 180 to 



315/1 from the tip of the tail. In the specimen 



noted as having 138 combs and spines, there appears 



to be a row of 4 very 

 small, anteriorly di- 

 rected spines close 

 together and just 

 anterior of the anus. 

 Wliile these struc- 

 tures seem unmis- 

 takable and hardly 

 apt to be artifacts 

 occurring in order- 

 ly, duphcating se- 

 quence, it would be 

 interesting to learn whether anything 

 similar occurs on related forms before 

 j^ 1 __ -^H assuming anything in regard to these. 



4 1 "t^B '^^® posterior branch of the uterus 



^ ' ""^^^ may terminate anterior or posterior 



of the anus. The 

 tail ends in a 

 blunt, rounded 

 end, bearing a 

 short spine. (See 

 fig. 4.) Whatap- 

 appears to be a 

 papilla occurs 

 near the end of 

 the tail. In the 

 posterior portion 



of the body the cuticular annulations are about 



5 /£ wide ; more anterior they are 7 /t ; in some 



places in the neck region they are about 16 /£. 



The eggs have shells averaging about 38 to 42 ,« 



long by 32 to 34 /i wide and about 3 or 4 /x 



thick. The eggs contain a well-developed embryo while in utero. 



The mouth structure is for the most part similar to that of the 

 male. (See figs. 5 and 6.) It is a little larger, the prominent 

 tooth at the base is 16 to 20 /i long and has on each side of it a pair 



^^^t^^^S^^^-^^^fai 



/(omfTi 



-RiCTULARIA SPLENDIDA. 



FEMALE. 



Komm 



Fig. 6.- 



DIDA. 



■RiCTULAEIA SPLEN- 



Head of female. 



