672 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.47. 



11. Cephalothorax thick and stout; trunk nearly as -wide as, or wider than, long. 12. 



11. Cephalothorax slender and linear; trunk considerably longer than wide 13. 



12. Genital process of extraordinary size, fully as large as one of the egg strings. 



quadrata (Bassett-Smith), 1896. 

 12. Genital piocess one-quarter the length of the trunk; second maxillae completely 

 fused; egg strings one-third longer than the trunk. 



uncinata (Muller), 1776, p. 680. 

 12. Genital process a mere ridge, scarcely projecting; second maxillae completely 



fused; egg strings snorter than the trunk recta, new species, p. 684. 



12. Genital process one-eighth the length of the trunk; second maxillae separate, 

 the base of each surrounded by a large wing alata Brian, 1906. 



12. Genital process one-eighth the length of the trunk; second maxillae entirely 



fused, without wings; head pointed forward, parallel with trunk axis. 



brevicolUs (M. Edwards), 1840. 



13. Trunk ellipsoidal, smoothly rounded posteriorly; bulla an elongate club; egg 



strings narrow and tapered posteriorly pagelli (Kr0yer), 1863. 



13. Trunk ellipsoidal, flattened, with a fleur-de-lis on the ventral posterior margin; 



egg strings narrow and cylindrical irina, new species, p. 685. 



13. Trunk ovoid, narrowed anteriorly, truncated posteriorly; egg strings thick 



ellipsoids denlicis (Kr0yer), 1863. 



13. Trunk ellipsoidal, smoothly rounded posteriorly; bulla a sphere; egg strings 



long cylinders dubia (T. and A. Scott), 1913. 



CLAVELLA PERFIDA, new species. 

 Plate 45, figs. 140 to 143. 



Host and record of specimens. — An adult female with egg strings, 

 and one attached male, and a young female with four attached males 

 were obtained from the gills of an Alaskan pollack, Tkeragra cTial- 

 cogramma, September 27, 1906, from a depth of 52 fathoms in the 

 northwest Pacific. The adxilt specimen is made the type of the spe- 

 cies and numbered 43505, U.S.N.M. The younger female, with the 

 attached males, is numbered 43589, U.S.N.M. 



Specific characters of female. — Cephalothorax much swollen and 

 inflated, longer than the trunk and tajDering gradually from the base 

 to the tip, bent back dorsaUy against the trimk; head not enlarged, 

 narrowed anteriorly; no dorsal carapace; base of neck with one or 

 two constrictions, as though segmented; trunk much wider than 

 long, convex ventrally, concave dorsally; genital process relatively 

 large and prominent, on a level with the ventral surface; egg strings 

 half as long again as the trunk, tapering slightly posteriorly; eggs 

 arranged in 12 to 14 longitudmal rows, about 25 eggs in each row. 



Fbst antennae indistinctly three-jointed, wholly inside the second 

 pair, tipped with a tuft of small setae; second antennae uniramose, 

 the terminal joints bent across the frontal margui and almost touch- 

 ing at the midhne; mouth tube reaching the posterior margm of 

 these antennae, broad and stocky; first maxillae tripartite, with a 

 small and poorly developed palp; second maxillae entirely lacking, 

 the attachment bulla being fastened to the surface of the trimk at 



