NO. 1123. 



pnocEEDixas of the xjtwxal museum. 793 



6. RHYNCHOBOTHRIUM BULBIFER, Linton. (Larva.) 



JVu/nchobothrmm bulhifer, LiNTOX, U. S. Fish Com. Kept., im], pp. 4S(!-18S, pi. x, 

 ' %s. 17, IS ; 1887, pp, 825-829, pi. xi, figs. 1 and 2. 



I liave met ou a few occasions larval WiynchohothrUi^ some of which 

 have been sufficiently developed to refer without doubt to this species 

 (:N^o. 5457, IT.S.K.M.), using tlie hooks as the principal criterion; others 

 have been referred with some doubt to this species. 



The specimens were all collected at Woods Holl, Massachusetts, one 

 lot from the filetish {Alufera sclioepni). August 12, 1S85. The other lots 

 are from the bluetish {Pomatomus saltatrix), one collected in August, 

 1884, another in July, 1887, three iu July, 1889, and two in August, 1889. 



One specimen from a bluetish agreed in the size and arrangement of 

 the hooks, and in character and dimensions of bothria, neck, and con- 

 tractile bulbs, with L\ bulhifer . Others from same host, very small, too 

 rudimentary for satisfactory identification, are probably the young of 

 this species, while others are more probably young of R. speciosum. 



The specimens from the filefish do not agree so well in size of con- 

 tractile bulbs, being shorter, and other dimensions shorter— i, e., head 

 and neck, 1.0 mm. in length, agree in the character of the hooks and 

 appear to be the young of this species. 



7. RHYNCHOBOTHRIUM LARVAE. 

 (Plates II, iigs. 12-16; III, tigs. 17-3.5; IV, figs. 1-2.) 

 I have found, on many occasions and in a great variety of hosts, 

 encysted Rln/nchohothria, which I have been unable to identify or can 

 determine only doubtfully. I here record such notes as I have made, 

 endeavoring to so group tlie dift'erent kinds as to make the notes of 

 some value to others for purposes of identification. 



I include here larval Rhynvhohothrln, from a number of hosts, which 

 have much in common, and probably belong to the same or to closely 



'related species, 



1. Notes of two rinds of RhyuchohothrUnn larva- in sea bass {Goitro- 

 pristes strlatus) have been made. Measurements on a specimen collected 

 at Woods Holl, Massachusetts, August, 1884 : Length, 1.03 mm. ; length 

 of bothrium, 0.18 ; length of contractile bulbs, 0.6 ; breadth of head, 0.23 ; 

 diameter of neck, 0.21; length of longest hooks, 0.026. The specimen 

 was encysted in the serous coat of the intestine of its host. The pro- 

 boscides were retracted ami the hooks of various styles, but their 

 arrangement could not be made out. They bear some resemblance to 

 those of R. longispine, Linton. 



Another from the same host and locality, collected August 6, 1886, 

 evidently the same, has hocJvS which agree in length with the other, 

 but rather sparsely distributed. The proboscides were estimated to be 



