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TRICOMA AND OTHER NEW NEMATODE GENERA 

 (With Fifty Illustrations in the Text). 



By N. a. Cobb. 



Introductory Note. 



This article is descriptive of twenty new species of Nematodes, 

 including ten new genera, found by the author at various times 

 since November, 1888. The worms are all free-living and marine, 

 having been taken from the Atlantic (Mediterranean), Indian 

 (Ceylon), and South Pacific (Australia) Oceans. The Mediter- 

 ranean and Ceylon species are described from specimens preserved 

 in balsam ; the Australian species are described also from speci- 

 mens in balsam, excepting the species of Monhystera, which were 

 examined fresh. 



Fi G. 1.— Diagram in explanation of the descriptive formula used for Nematode worms ; 

 6, 7, 8, 10, 6 are the transverse measurements, while 7, 14, 28, 50, 88 are the 

 corresponding longitudinal measurements. The formula in this case is :— 

 7- 14- 28- 50- 88- 

 6- 7- 8- 10- 6- 

 The unit of measurement is the hundredth part of the length of the worm, 

 whatever that may be. The measurements become, therefore, percentages of 

 the length. 

 The measurements are taken with the animal viewed in profile ; the first is taken 

 at the base of the pharynx, the second at the nerve-ring, the third at the 

 cardiac constriction, the fourth at the vulva in females and at the middle (M) 

 in males, the fifth at the anus. 



1. Tricoma, new genus. 



The worms belonging to this genus will in future be readily 

 recognised by the unusual appearances presented by the cuticula. 

 The striations are so coarse as to sugerest the segmentation 



