4 PROCEEDINGS OF THE NATIONAL MUSEUM vol.75 



uterus are so massed together that the usual ascending and descend- 

 ing branches are not distinguishable. The transverse coils of the 

 uterus occasionally extend almost to the margin of the body. The 

 vitellaria consist of large aggregations of glands connected by rather 

 narrow longitudinal ducts forming a moniliform band, which stretches 

 on each side from a point just posterior to the vesicula seminalis to 

 about the equator of the body. The transverse vitelline ducts were 

 not conspicuous. The eggs in the posterior coils of the uterus are of 

 a golden yellow color, but become darker as they advance toward 

 the metraterm. In this part of the uterine tube, which passes directly 

 under the acetabulum, the eggs measure 44ju to 48.2^t in length by 

 28.3)u in width; they have a slight shoulder, and are operculated. 



Host. — Colohus species. 



Location. — Liver (bile ducts). 



Locality. — Ituri Forest, Belgian Congo, May 21, 1927. 



r^/^e.— Cat. No. 8012, U.S.N.M., Helm. Coll.; Cat. No. 8013, 

 U.S.N.M. 



Paratypes. — Helm. Coll. 



SYSTEMATIC POSITION 



The species described above is a typical member of the genus 

 Dicrocoelium Dujardin, 1845, the number of species of which are 

 numerous. They are distributed in a cosmopolitan manner in reptiles, 

 birds, and mammals, usually occupying the bile and pancreatic ducts. 

 The course that the intestinal ceca pursue, external to the line of 

 vitelline glands is rather unusual, but the present species shares this 

 character, at least, with D. Jiospes Looss, 1907, found in Egyptian 

 cattle, and with D. macrostomum Odhner, 1911, of Numida ptilorhyncha 

 from the White Nile. The present species resembles D. macrostomum 

 to a remarkable extent, the two forms being almost identical with 

 regard to the size and disposition of the organs. The only differences 

 that can be detected from Odhner's description of the species concerns 

 the inconspicuousness or absence of a receptaculum seminis (not 

 mentioned in D. macrostomum) and a slightly greater length of the 

 intestinal ceca relative to the total length of the body. The former 

 difference may be apparent rather than real, depending upon the 

 physiological condition of the genitalia at the time of examination, 

 and the latter difference is so small as to be of doubtful significance. 

 It seems, however, rather unlikely that the present material coming 

 from a monkey is identical with the flukes from a bird derived from 

 a totally different locality. For this reason, it is proposed to credit 

 the two points of morphological difference, noted above, with specific 

 value. The name, D. colohusicola, is provisionally proposed for the 

 material under consideration, pending the opportunity for making a 

 comparative examination with D. macrostomum. 



