FREE-LIVING NEMATODES 



85. 

 ~ 2 . 



-H 



T.T 



which are resolvable into rows of dot-like markings 6 modified on the lat- 

 eral fields, 7 where there are distinct wings to the cuticle, 8 one on each side 

 of the lateral lines. The N \ 

 excretory pore is located 

 near the lips, 9 and the 

 tail end is armed with ph 



iii! i sp 



caudal glands and a spin- 

 neret. 10 The oesophagus has a posterior or cardiac bulb two-thirds as 

 wide as the base of the neck. 11 The two ovaries are symmetrically ar- 

 ranged, reflexed, and occupy 19 per cent of the length of the body. 12 

 And, similarly, the male internal sexual organ is single and outstretched, 

 and occupies 56 per cent of the length of the body. 



Among the dredgings at Ross Island were three containing nematodes 

 which furnished material for this report. These three were marked: 

 (1) "Bay, Cape Royds, in 10 to 20 fathoms of water, May 81, 1908;" (2) 

 "Cape Royds, in 25 to 50 fathoms of water, July, 1908;" (3) "Bay, 

 in 13 fathoms of water, April 30, 1908." These are referred to in the 

 following descriptions as, (1), Bay, Cape Royds; (2), Cape Royds; 

 and (3), Bay. 



Terminology relating to Striation of Cuticle. 



The camera lucida sketches are all made to the same scale, namely, 

 a magnification of 750 diameters, except in the case of Thoracostoma, 

 which was drawn at 400 diameters. The sketches may be relied upon 

 as accurate. Information in the keys is not repeated elsewhere. 



8 Dots above and below the line between the second and third terms. 



7 Modified dots outside those just mentioned in 6. 



8 Lines above and below the formula line between the second and third terms. 



9 Oblique line near the pharyngeal terms of the formula. 



10 Angular mark at right-hand end of formula. 



11 Underscoring the third diametral measurement, thus indicating the presence 

 of a bulb. Length of mark indicates the size of the bulb. 



12 Curved marks before and after 47, and 19 used as an exponent figure. 

 NOTE : Absence of any particular mark indicates the absence of that particu- 

 lar feature so far as at present known. 



