864 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [146] 



cides are retracted it is usually globular, often truncated at the apex. 

 Again it may be elongated glandiform or pyriform on account of a con- 

 striction behind the bothria. 



The bothria, four in number, are opposite and of varied appearance. 

 In some cases they are sessile and difficult to see, in others they are 

 elevated on low papillae. The latter usually stand at right angles to 

 the axis of the body, although in cases where the proboscides are re- 

 tracted, they are sometimes directed forward. In one case they were 

 so arranged as to give to the head a decidedly cuboidal shape. In this 

 case the diameter of the head was .36 mm , the outside diameter of a tubu- 

 lar bothrium was .08 mm , the inside diameter .04 mm . Seen from the front 

 the bothria made the four corners of a square. The bothria are some- 

 times on the anterior part of the head, this of course only when the 

 proboscides are retracted, sometimes about the middle. 



The most remarkable changes take place in the head when the ten- 

 tacular proboscides are protruded in whole or in part ; these proboscides 

 are sixteen in number ; among the lot of thirty specimens, more or less, 

 there were fortunately four or five which had the proboscides protruded, 

 and of this number two at least in which they were fully protruded so 

 as to form a terminal rosette- like cluster, made by the sixteen radiating 

 tentacular-like proboscides. It is probable that these organs can be ex- 

 tended farther than was indicated in the alcoholic specimens. In one 

 specimen the head was ,5 mm in length, including the terminal rosette? 

 diameter of head behind bothria, .16 mm j diameter of rosette, .34 mm ; length 

 of bothria! papilla about .06 mm ; diameter of first segment .06 mm . 



Only a few of the more frequent shapes which these scoiices assume 

 have been mentioned, but enough have been alluded to which, together 

 with the sketches, should make future identifications reasonably cer- 

 tain. It is to be hoped that the polymorphous character of the head of 

 this species may not be made the occasion of multiplying species un. 

 necessarily. 



An illustration is here afforded of the importance of preserving every 

 specimen, and of not neglecting what may appear to be unimportant 

 fragments. It is certainly possible to have obtained one-half of the 

 specimens of this species that are in my collection without finding any 

 that show the real structure of the head . 



The proboscides are soft, tentacle-like, slender when fully extended • 

 they are probably extended by evagination, although of this fact I am 

 not yet certain ; when all are fully extended they are found to be exactly 

 sixteen in number, and form a terminal crown or rosette j in this con- 

 dition they resemble the expanded tentacles of a sea-anemone. Some- 

 times only a few of these tentacles are protruded, and in one instance 

 a single tentacle arose from the apex of the head and was surrounded 

 closely by the four bothria ; if found by itself it would have been a puz- 

 zle indeed and might have furnished the type of a new species. The 

 longest tentacle that was observed measured .2 mm in length, and was 



