HELMINTHES : COLOMBO MUSEUM. 181 



Di'plochetos, u .gen . 

 Genital pores marginal bilateral : genital glands in only one 

 group ; at the scolex a double crown of hooks ; testes numerous ; 

 three layers of longitudinal muscles ; segments much broader 

 than long ; uterus with ventral orifice right and left of the 

 middle line. 



46. — Diplochetos volvulus, n.sp. 



PI. II., figs. 30-31. 



Intestine of Yellow-wattled Lapwing, Sarciophonis malabari' 

 cus, Bodd.; Weiigatta. 



Length 8'5 ; anterior segments 0*018 long x 0*21 broad, 

 middle segments O'lO x 0*40, posterior 0'37 x 0*70, always 

 broader than long. The pyriform scolex is 0*35 broad x 0*26 

 long ; the rostellum carries twenty-four hooks in two circles of 

 twelve, the hooks O'OlT long ; in the parenchyme are three layers 

 of longitudinal muscle-bundles, which become stronger towards 

 the interior ; on each side two strongly sinuate vessels, the dorsal 

 larger ; the nerve runs along much nearer the margin ; calcareous 

 deposits not present. Genital pores marginal, right and left in 

 each proglottid ; the cirrus-sac occupies i of the cross-diameter 

 and contains coils of the vas deferens; entad of the cirrus-sac 

 occl^r extensive convolutions of the vas deferens; the vagina 

 lies ventral to the cirrus-sac and expands into an irregularly 

 shaped receptaculum semitiis which reaches about ^ of the cross- 

 diameter. In each transverse section about ten oval testes are to 

 be found. The ovary lies in the inner third of the medullary 

 substance and consists of separate follicles ; the round vitellarium 

 lies ventrally in the middle ; the site of the uterus breaks 

 through the musculatl^re and parenchyme ventrally about 5 

 of the cross-diameter from the margin, sometimes to the right, 

 sometimes to the left without opening to the exterior ; I have 

 not found it in full development. The eggs are 0"016 long 

 X 0*013 broad. Other Tteniid genera with biserial genital pores 

 are the following : — 



Diploposthe, with simple hook-crown and three testes in each 

 segment. 



Amahilia, with double cirrus-sac and simple vagina opening 

 ventrally. 



Diplophallus, with double male organs and simple female 

 organs. 



Dipylidium, with several rings of hooks on the rostellum and 

 elongate segments. 



The large genera from ruminants and rodents do not concern 

 the question. 



