ABT. 26 FOUR NEW TEEMATODE WORMS MacCALLUM 7 



The peculiar characters may be summarized as follows : Parasites 

 on gills of Sphyrna zygaena; measurements, 8 mm. by 0.5 mm. ; ap- 

 pendix as prolongation of fixation disk; intestinal projection in both 

 disk and appendix; hooks smooth, bent at right angle; eggs with 

 stout filament at each end ; thick-walled cirrus. 



Type specimen.— V).'^:^M. Helm. Coll. No. 8136; paratypes 

 No. 8137. 



SQUALONCHOCOTYLE VULGARIS Cerfontaine 



Plate 1, Figxjke 4 



This worm, found on the gills of the dusky shark {C arclmrinus 

 7nilberti), measures about 5 mm. by 1.5 mm. It is apparently the 

 same as that described by Cerfontaine as found on the gills of Mus- 

 telus vulfforis, although he mentions its length as 12 mm. 



The mouth sucker is large and strong and surrounded by a bell- 

 shaped fold of skin, which is covered with great numbers of minute 

 tubercles, or nodules. Even the edge of the sucker itself is rough- 

 ened with them. About the esophagus and pharynx there are masses 

 of cells that may act as a salivary gland or even produce a hirudin- 

 like substance. There is a small pharynx, and the intestines, which 

 are filled with a black pigment, are branched on inner and outer sur- 

 faces. The pigmented prolongations after the union of the ceca run 

 down into the appendix and the fixation disk. 



The hooks of the large suckers measure 320/a from tip to tip (fig. 

 1, d). The lips of the sucker are edged with tiny teeth and these 

 too, or small tubercles, are scattered over the lining. The small 

 booklets in the appendix measure about 50/a in length (fig. 1, d'). 



The genital pore lies just behind the bifurcation of the intestine. 

 The penis is a pear-shaped mass covered over with minute, red- 

 stained eminences, which seem to be cells and certainly not a chiti- 

 nous armature. The uterus in every case is enormously distended 

 with a mass of eggs, usually more than a hundred, so that it occu- 

 pies the whole central part of the body. The eggs are spindle-shaped 

 and measure 200/^ by 56jit. They have a straight filament at each end 

 about as long as the egg. The vaginal orifices are not, as described 

 by Cerfontaine in his S. vulgaris, situated far toward the margin of 

 the body, but lie inside the bend of the intestinal ceca. The vaginae 

 run separately to join the vitelline duct. The ovary is large, lobu- 

 lated, and folded. One can not see a receptaculum seminis on ac- 

 count of the crowding of the overfilled uterus, but it is described by 

 Cerfontaine. There are about 20 testes in the middle of the body. 



Specimens examined.— V. S. N. M. Helm. Coll. No. 8183. 



SQUALONCHOCOTYLE CANIS Cerfontaine 



Parasites apparently identical with those named S. canis by Cer- 

 fontaine, and found by him on the gills of GaJews canis, were found 

 on the sills of GaTcKarinus linibatus. 



