2 PRECEEDINGS OF THE NATIONAL MUSEUM vol. 70 



slips, or on a slide with cover slip, and using such pressure as was nec- 

 essary to crush the ripe eggs, a procedure which required more force 

 than we had expected, several embryos were forced from their shells. 

 These were rather blunt and had smaller tails than the embryos from 

 eggs on C. coimnersonli. They were quite different from the free- 

 living nematodes which are often found with them and which are 

 larger, very active, and have a sharp tail. These latter are often 

 seen in the fluid containing an amount of mucus and other debris 

 from this shark and belong to the genus Monhi/sfera. 



As the worm eggs described here are from the membranous mucous 

 covering of the connective tissue of the gill arches of C. milherti and 

 as the egg shells are spiny, they are regarded as a distinct species. 

 This species I propose to call Capillaria spinosa. 



In looking for the spiny eggs we discovered eggs of another form. 

 They are spherical, of a light grayish color, and contain a coiled 

 embryo. The embryo appears to be granular as seen through the 

 shell; when extruded from the shell it is sluggish and is somewdiat 

 granular throughout its whole length. We have never seen it lively 

 or seeking around for food, as is often the case with nematodes. 

 These eggs are very dilSicult to mount. This egg does not seem to 

 have been noticed hitherto. The adult worms were not seen. The 

 eggs are about 100/* in diameter and almost always are solitary, 

 although as many as two or three may often be seen in the field of the 

 microscope at the same time. Owing to the entire lack of a recog- 

 nizable character about these eggs on which to refer them to a 

 known nematode group, no name is attached to them here. 



I may say that the accompanying illustration, which has been 

 made in Dr. N. A. Cobb's department, is quite true to nature and 

 meets with my approval. 



REFERENCE 

 MacCallum, G. a. 



1925. Eggs of a new species of nematoid worm from a shark, Proc. U. S. Nat. 

 Mus., Wash., vol. 67, art. 16, pp. 1-2, pi. 1, figs. 1-3. 



o 



