178 TAPEiroRMS OF HAliES AXD UABUITS—STILES. 



Riehm^ in 1881 studied the tapeworms of rabbits and hares, and in 

 a pioliininary account of liis work described this same form as Citto- 

 taitid J(ttissi)ii((, now f^enus, new s])ecies. Later- lie ])lacod this species 

 in the genus Dipt/Udiitm witli the following specitic diagnosis: 



Kopf hakeulos iiber f mm. brcit, mit starlv vor8j)riug(m<lcu Saugniipfeu und 

 dadurch gegen die lanzettformig sitli verbreiternOo Gliederkette deutlich abgesetzt. 

 Geschlecbtsuflnniigen beiderscitp, in den zitzenartig vorspringendcn Hinterecken 

 der Glioder, ■welcho den liiindern, bcsonders der coutrahiertcn Tbiero ein gefranztes 

 Anseben verleiben. Glioder stets viel kiirzer als breit nnd nnmcntlicb nacb den 

 Seiten bin nngemein dick. Liinge im gestreckten Zustaude bis 80 cm., Ihcitc der 

 reifsteu Glieder 15 nmi. nnd dariiber Wobnthiei': Lcptis euuicuhis. 



Of anatomical details he gives the followiiig, which ai)])ear to nic to 



be of importance: 



Segments may attain 3 to 'SJ> mm. ia tbickncss; tlie strol»ila is generally Ibuiid in 

 the lower portion of tbe small intestines and is of a grayisb to a rcddisb gray 

 in color, sometbiug like Ihihnoccjjlialiix laiiis. Black pigment on tbe suckers and 

 genital pores. Suckers prominent; neck sliort. Genital anbigen appear very early. 

 Male oro-ans: Testicles very numerous, 0.11.5 mm. in diameter, scattered tbrongbout 

 dorsal portion of median tield; cirrus poucli large, provided with three layers of 

 mucles, two circular and one longitudinal layer, cirrus is generally protruded. 

 Female organs : Vagina opens close to cirrus, and is quite tbin ; median to tbe longi- 

 tudinal canals it swells into a receptaculum seminis; female glands essentially the 

 same as in Dipylidiitm peciinatiiiti, but situated very close to the longitudinal canals. 

 The uterus is described "not as a simple tube, widened here and there, and running 

 transversely through the segment, but it is broken up into two or three such tubes, 

 which unite here and there, and thus cut the parenchyma up into islands. This 

 structure is seen, however, only in segments without eggs. Through the pressure of 

 tbe developing ova these tubes widen so that tbe islands of parenchyma are sup- 

 pressed and the uterus then appears as a single tube." In some segments an extra 

 (third) set of female glands was observed right or left of the median line. Excre- 

 tory system very highly developed; in the younger segments it is composed of a net- 

 work of canals, with one lateral canal which is especially large; transverse canal 

 with numerous anastomoses present ; as tbe genital organs develop, tbe canals of the 

 median field become more or less suppressed, but three or four lateral canals persist 

 each side and tbe transverse canals at the posterior margin become larger, so that 

 the excietory system now bears more of a resemblance to that of IHpylidium pectina- 

 tiim ; tbe second canal systeju (dorsal <'anal) resembles tbat of Dipiil'uHiim hnvkarti. 

 (Abstract.) 



Neumann' in 1888, places this worm in the genus Twiiia. 



BlanchardMn 1891 examined Baird's specimens and recognized them 

 as identical with D. latissimuni, Kiehm. He also examined fresh speci- 

 mens, which he describes in some detail. 



Strobila measures 40 to 50 cm. long and contains about 210 segments ; head, 0.8 nmi. 

 broad by 0.03 long. Neck absent, segments may attain 4 mm. in length by 15 in 

 breadth. Genital pore appears about tbe seventy-eighth segment; in the older seg- 

 mnets it is more ilistal than in the younger segments; egg is spherical 52 to 60 /<,• 

 bulb of pyriform body 16 to 24 >u, boms long and curved. (Abstract.) 



i[Untersuchungen an den BandwMinuern der llaseu und K.ininchen, Zeitschr. ges. 

 Naturw. 3 ser., VI, 1881, p. 200. 



^Studien an Cestoden, Zeitschr. ges. Xatnrw., 3 ser., \1. 1S81. pj). .5S:^-590. 



'Trait/' des maladies ])arasitaires, p. I'JO, Paris, 1888. 



••Mem. Soe. zool. Frame, IV, 18!U. pp. Ill, 151, 452-457, ligs. 21-25. 



