323] PSEUDOPHYLLIDEA FROM FISHES— COOPER 35 



are merely short median grooves which unite at the very tip not only with each 

 other but with a frontal median groove which passes laterally into sUght emar- 

 ginations of the edges of the segments. While these emarginations were seen 

 to be present in the anterior segment, gradually disappearing towards the mid- 

 dle of the worm, no such "flat leaflike flaps (bothria) on the lateral margins 

 separated from each other on flat surface by a broad, shallow sulcus," as de- 

 scribed by Linton (1898:428) and sho^^^l in his Fig. 4, PI. XXVIII, for the 

 first segment were met with; but the posterior border was quite entiie, altho 

 as seen in figure 3, not very prominent in the vicinity of the median li,ne in 

 adults as well as in larvae. The bothria of the mature specimen (H. 7 of the 

 table below) were not present, but the region where they would otherwise be 

 was quite smooth, only a shallow, median, frontal groove appearing. The whole 

 strobila is ovate-lanceolate, considerably depressed and provided in the adult 

 with a very shallow median groove on the dorsal surface (Fig. 80) which seems 

 to be due to the slight protrusion of the median reproductive organs, chiefly 

 the cirrus-sacs and seminal vesicles, towards the ventral surface (Fig. 79) and 

 the consequent dragging downward of the dorsal median tissues. Concerning 

 this matter Linton said "5. dimorphus is described as having in the larval 

 state a longitudinal median furrow on each face. These specimens do not 

 exhibit this character; neither do they have anything that can be properly 

 called a costa dividing the two bothria. " While in the specimens studied the 

 dorsal groove was present not only in the adult but (not so well marked) in 

 the larva, a similar ventral groove was also noticed in sections of the anterior 

 end of one of the latter. Both grooves, however, are in either case so shallow 

 as- to be easily overlooked in alcohoHc specimens; they seem to be of only second- 

 ary importance since they are apparently quite variable in their nature. While 

 the segments in the anterior region of the strobila are very broad and com- 

 paratively thick, short, and from 0.1 to 0.5mm. in length, posteriorly the stro- 

 bila is considerably smaller and flatter, especially in mature individuals. In 

 larvae the segments are much more irregular in outline and as much as 1mm. 

 long (0.75 in the only ripe specimen studied). The segmented condition of 

 the strobila, in contrast with that of Ligula, is rendered more apparent by the 

 prominent posterior borders of the anterior and middle proglottides which at 

 the margins produce the characteristic saw-tooth effect. The following 

 table gives the measurements of two specimens with those by Linton for 

 comparison : 



