NO. 1573. PARASITIC COPEPODS— WILSON. 409 



sequent authors. In Leach's paper the species carcliarise is given 

 first and by the law of priority ought to be taken for tlie name of the 

 species, while cranchii became a synonym. But unfortunately the 

 type of carcharisR has never been seen by any other investigator, and 

 hence the species can not be identified with certainty. On the other 

 hand, the original type of cranchii has been examined and figured <^ by 

 Milne Edwards and others and can be identified accurately. There- 

 fore preference in the present instance is given to that name which 

 is open to the least doubt. 



In 1840 Milne Edwards published three species, pallidus, vulgaris, 

 and dentatus, which so far as can be made out from the descriptions 

 he gave, and also from his figures of the last-named species, are iden- 

 tical with cranchii. At all events they do not deserve to be made 

 anything more than varieties. 



In 1852 Dana published the species concinnus, which like Milne 

 Edwards's pallidus appears to be the young of the present species 

 before they have acquired the dark pigment which colors the cara- 

 pace and dorsal plates so conspicuously in more mature specimens. 



Dana says nothing of the color of his species, but he does say 

 "bod}' translucent or subtransparent," which certainly could not 

 be the case if the pigment were present. Neither author gives the 

 details of the appendages, and judgment must be based upon the 

 general make-up of the body and the relative shape and proportion 

 of its various parts. As these are practicalh' identical, concinnus 

 must be placed as a synonym of the present species until proven to 

 be distinct. 



The U. S. National Museum Collection has a fine set of specimens 

 illustrating this species. We may refer again to the fact that Cranch, 

 for whom the species is named, found both males and females prob- 

 ably on the same fish. Steenstrup and Liitken record two similar 

 instances in wliich Captain Hygom obtained the sexes together. 



And here in the National Museum Collection there are three addi- 

 tional lots in which both sexes came from the same fish. 



Of the female specimens we find Cat. Nos. 6019 and 6020, U.S.N.M., 

 from Oarcharhinus ohscurus, taken at Station 1142 off Marthas Vine- 

 yard, and containing one and two females respectively. A single 

 male was obtained at the same time and is Cat. No. 6031, U.S.N.M. 



A second lot, consisting of six males, Cat. No. 8640, U.S.N.M., and 

 five females, Cat. No. 8641, U.S.N.M., was obtained from a large 

 shark at the surface at Station 2237 by the Albatross in 1884. 



The third lot contains ten females, Cat. No. 10746, U.S.N.M., two 

 young females. Cat. No. 32741, U.S.N.M., and a smgle male, Cat. No. 

 32752, U.S.N.M., obtamed from a 10-foot shark at Station 2422 

 by the Albatross in 1884. 



a Atlas du Kfegne animal de Cuvier, Crustaces, pi. lxxviii, figs. 2, 2 a. 



