424 BULLETIN OF THE BUREAU OF FISHERIES. 



F 1 1 ; . 129. — Rhynchobothrium sp.. from sharp-nosed shark (Scoliodon terrse-novse). Lateral view of head. 



Life. 

 Fi<i. 129a. — Front view of same . Life. 



Fig. 130. — Same species, head and neck, alcoholic specimen. Actual diameter of bothrium 1.12 mm. 

 Figs. 130a and 130c. — Different views of proboscis; larger hooks on medial side. Actual diameter of 



proboscis, excluding hooks, 0.15 mm. 



PLATE XVIII. 



Fig. 131. — Rhynchobothrium sp., from sting ray (Dasyatis say). One view of proboscis, sketched from 

 specimen in balsam. Actual diamter, excluding hooks, about 0.09 mm. 



Rhynchobothrium plicatum, sp. now, from bonnet-head shark (Sphyrna liburo). 



Fig. 132. — Head, neck, anil anterior segments. Life; X 50. 



Fig. 133. — Outline of median and post-median segments. • .Ml. 



Fig. 134.— Median segment. Life; X 80. 



Fie. 135. — Segment toward posterior end. Life; X 50. This specimen was stained and mounted in 

 glycerin when a conspicuous rudiment of the uterus became visible along the median line 

 which was not seen in the living specimen and is not included in the sketch. 



Fig. 136. — Posterior segment. Life. Actual length about 3 mm. 



Fig. 137. — Ova. X 210. No bristles were seen on these ova, although in another segment of the 

 same worm ova were seen with bristles as shown in the next figure. 



Fig. 138. — Ovum armed with bristles. X 540. 



PLATE XIX. 

 Rhynchobothrium plicatum, sp. nov., from bonnet-head shark [Sphyrna tiburo). 



Fig. 139. — Immature specimen. Life; actual length 4.8 mm. r, Patch of red pigment. 

 Fig. 140. — Another with scolex partly retracted. Life; actual length 4.5 mm. 



Otobothrium insigne, sp. nov., from dusky shark ( Carcharhinus obicwrus). 



Fig. 141. — Sketch of specimen mounted in balsam. Actual diameter of head 1.2 mm. 6, Contractile 



bulbs; s, proboscis sheath. 

 Fig. 142. — Same, more enlarged. 



Fig. 143. — View of another specimen, also in balsam. Actual diameter of head 1.35 mm. 

 Figs. 144 and 145. — Views of opposite sides of the same proboscis at about the same level. Actual 



diameter, excluding hooks, 0.06 mm. 



Rhynchobothrium hispidum Linton, from the sting ray {Dasyatis say). 

 Fig. 1411. — Strobile. Life; /,. 50. r, Red pigment. 



PLATE XX. 

 Microcolyle sp., from gill of blue-fish ( Pomatonvus saltatrix). 



Fig. 147. — Sketch of damaged specimen. Life; actual length 1.S5 mm. 



Fig. lis. — Cirrus of same, diagrammatic. X 525. 



Fig. 149. — One of the small suckers from posterior end of another specimen. Actual length 0.042 mm. 



There were about 50 pairs of these suckers. 

 Fig. 150. — Hooks from cirrus; actual length about 0.015 mm. 



Dactytocolyle sp., from menhaden (Brevoortia tyrannus). 



Fig. 151. — Sketch of damaged specimen. X 66. or, Posterior lobe with hook, more highly magnified. 



THstomum appendiculatum Rudolphi. 



Fig. 152. — Dorsal view. From hog-fish (Orthopristis chrysopterus) . Life; actual length 1.20 mm. 

 Fig. 153. — Same from sea robin [Prionotus tribulus); ventral view. Actual length 1.12 mm. 



