SOME MAMMALIAN TAPEWORMS, 649 



open to side and in front of vagina and pass back along ventral 

 margin of roivs of testes. In fidly mature segments sperm-ducts 

 increase in volume. Ovaries double, i^entral and posterior in posi- 

 tion, in front of transverse excretory vessel, formed of numerous 

 club-shaped masses radiating from common centre. Vagina 

 unu,sually wide, showing a marked receptaculum seminis in less 

 fidly mature jn'oglottides ; the loidth increases enormously in the 

 ftdly mature proglottides until it is nearly as loide as the proglottid 

 is long. Genital cloaca short. Uterus single, sac-like, ivithout 

 definite outgrowths, hut sometohat irregular in form, filling most of 

 the proglottid. The eggs without W-shaped apparatus, tvith a 

 thinner inner shell and a very wide and lax outer membrane. 

 Proglottides apparently not detached singly, but in groups-.- 



Hab. Cercopithecus callitrichtis. 



It is clear from this definition that the Tapeworm now under 

 consideration has been rightly referred by me to the genus 

 Bertiella. There is, I think, no other genus which shows the 

 same assemblage of characters as those which 1 have just set forth 

 in brief. It remains to be seen what position the species occupies 

 within the genus, of which we now know a good many different 

 species. 



It seems that we may select the following characters as 

 distinctive of this species, which will be thus definable : — 



Bertiella cercopitheci, sp. n. 



Length 150 mm. or more, breadth 10 mm. posteriorly, gradually 

 tapering to head. Scolex tvith black pigment scattered throughout 

 middle of scolex and forming a special layer round each sucker. 

 Suckers directed anteriorly, and completely retractile. JVo neck, 

 strohilisation commencing at once. Lateral 7ierve-corcl divided into 

 three, the middle one the largest. Lateral tvater-vessels sujjerjjosed , 

 the dorsal much the smaller. Testes extending between ivaier -vessels, 

 forming a layer two or three deep and three or four ivide in middle 

 region of pti'oylottid, more numerous laterally. Vesicula seminalis 

 very long and coiled, extenditig into cirrus sac. Vagina divisible iiito 

 two well-marked regions and communicating by very narroiv interval 

 ivith tvide receptaculum seminis. Eggs ivithout pyriform ajjparatus. 



Hab. Cercopithecus callitrichus, in colon (?). 



Following the subdivision of the species of Bertiella by 

 Zschokke * into three groups, the present species evidently 

 belongs to the first group, to which Zschokke assigned Tmnia 

 mucronata and T. conferta of Meyner f. Bertia studeri and 

 B. satyri of Blanchard % are doubtfully admitted by Braun § into 

 the genus Bertiella as recognised by the better-known species fully 

 described by Meyner, for Blanchard does not describe the genital 



* " Neue Studien an Cestoden aplacentalev Savigethiere," Zeitschr. wiss Zool 

 Ixv. 1897, p. 404. 

 t " Zwei neue Ttenien aus Affen," Zeitschr. f. Naturw. 1895, p. 1. 

 X M6ni. Soc. Zool. France, 1891, p. 186. 

 § Bronn's Klassen u. Ordn. des Thierreich, iv. Abth. 1 b, p. 1712. 



