[51] NOTES ON ENTOZOA OF MARINE FISHES. 7G9 



I found some difficulty in ascertaining the exact number of costoe 

 and resulting loculi, on account of a tendency on the part of the bothria 

 to curl up at the free ends. The arrangement of the costa; is as follows : 

 A thick double muscular band traverses the middle of the face of each 

 bothri um from tip to tip, like the keel plank in the frame-work of a 

 skiff. From this middle partition numerous ribs rise, curving outward 

 and upward to unite in a thick crenulated rim, which forms the border 

 of the bothrium. To carry out the figure of the skeleton of a skiff, the 

 curving costte answer to the ribs, and the thick crenulated rim to the 

 gunwale. The costre are arranged with perfect symmetry on the two 

 sides. I am not yet certain as to the exact number of these costa?, nor 

 am I certain that the number is precisely the same in every individual. 

 I have counted as many as were in view and estimated the number in 

 concealed and obscure parts with varying results, viz, from thirty-two 

 to forty and upwards on a side, thus making, in round numbers, from 

 sixty to eighty loculi on the face of each bothrium. The bothria have 

 a tendency to bend abruptly at the middle on a transverse hinge-like 

 iue. The margins of the bothria are usually slightly notched at the ex- 

 .reuiities of the hinge. The head of the living worm is almost transpa- 

 ent and the bothria are exceedingly active. On account of their trans- 

 parency and gracefully curving outlines they are very beautiful objects, 

 lie pedicels were not observed to contract or lengthen appreciably, and 

 in the preserved specimens they have changed their proportions but 

 slightly from what they were in life. In the alcoholic specimens the 

 pedicels have about the same diameter as the neck, or a little greater, 

 nd their length does not quite equal their diameter. They appear to 

 be arranged cruciformly. The bothria in the 1 alcoholic specimens are 

 variously bent. In some their free ends are turned towards the axis of 

 the body and so curled up as to give the head an almost globular out- 

 line. In others the bothria are turned in the opposite direction. The 

 pedicels, as to their origin, are like so many forks branching abruptly 

 from the apex of the neck, and the bothria are like a terminal whorl of 

 four petiolulate leaflets at the summit of the petiole of a compound 

 leaf. There is, therefore, scarcely anything that can be called a head, 

 if the bothria and their pedicels are disregarded. The short, cylindri- 

 cal neck is, in some cases, slightly enlarged a short distance back of 

 the head. 



In five specimens of the lot of about twenty-five there was a small 

 red spot in the center of the neck near the base of the pedicels. There 

 do not seem to be any correlated features to distinguish these speci- 

 mens with the red spot in the neck from the others in which no red 

 spot is visible. 



The two sorts were placed in different vials at the time of collecting, 

 but the red coloring matter is dissolved out by the alcohol, so that when 

 I came to study this species after they had been preserved for some 

 months, there is nothing but the label on the vials to tell that there was 

 ever any difference between the two lots. 

 H. Mis. 133 49 



