NO. 1573. PARASITW VOPEPODS— WILSON. 403 



pigment, while the mature adults may be densely colored with it. 

 Every lot of specimens containing more than a few individuals shows 

 these variations. The U. S. National Museum Collection contains but 

 a single lot of this species, Cat. No. 8120, U.S.N.M., obtained from 

 a dogfish off the coast of Shetland. 



Evidently this is a European species, since nearly every European 

 author mentions it, while it has not yet been found on tliis side of 

 the Atlantic. 



PANDARUS CRANCHII Leach. 



Tlate XXVIII. 



Pandarus cranchii Leach, 1819, p. 535. 

 Pandarus carcJiarisc (?) Leach, 1819, p. 535. 

 Pandarus pallidus Milne Edwards, 1840, p. 468. 

 Pandarus nilgaris Milne Edwards, 1840, p. 468. 

 Pandarus dentatus Milne Edwards, 1840, p. 469, pL xxxvm, fig. 19. 

 Nogaus latreillii Leach, 1819, p. 536 (male). 



Pandarus cranchii Milne Edwards, Atlas du Regno animal, pi. lxxviii, figs. 2 a 

 to d. 



Female. — Body obovate, strongly narrowed posteriorly; carapace 

 somewhat wedge-shaped, widest posteriorly, with the lateral mar- 

 gins only slightly rounded. Frontal plates wide and prominent at 

 their outer ends, thin and linear toward the mid-line. Eyes situated 

 far forward, visible in those specimens which have no pigment or in 

 wliich there are large clear spaces at the center of the carapace; 

 concealed in the heavily pigmented specimens. 



Posterior margin of carapace a shallow reentrant curve, armed with 

 seven to ten large spines or teeth along the center. 



The posterior corners are short and wide and stand out j^rominently 

 beyond the first pair of dorsal thoracic plates. 



The teeth are separated a greater distance from one another than 

 their own length and reach backward nearly to the posterior margin 

 of the central plate of the second thorax segment. 



Dorsal plates of second segment much enlarged, more than twice 

 the length of those on the third segment, and reaching beyond the 

 center of those on the fourth segment. They are slightly enlarged at 

 the base, but the tip is also broad and evenly roimded. 



Plates on the third segment nearly as long as the free portion of 

 the following pair, with a broad and deep central sinus. 



Plates on the fourth segment overlapping almost the whole of the 

 genital segment, broad and evenly rounded with a shallow central 

 sinus. In young females these plates do not reach much beyond the 

 center of the genital segment; in mature adults they often reach its 

 posterior margin. 



Genital segment obovate, strongly narrowed posteriorly and j^ro- 

 duced into a long triangular point on either side of the sixth segment 



