1888.] NATURAL SCIENCES OF PHILADELPHIA. 167 



the body became more uniformly translucent, without however af- 

 fecting the white opacity of the intestines. The generative apparatus 

 appears to be undeveloped, as no distinct organs were observable. 

 At the middle of the posterior portion of the body, in the usual posi- 

 tion of the testes, there appeared a single clearer spot, and in advance- 

 of it a clearer streak. The character of these he had not determined. 



Many worms, the Echinorhynchus proteus, clung to the interior of 

 the intestine its whole length, but they were not so numerous as, nor 

 larger than, they are commonly found to be in smaller individuals 

 of the same fish. 



Of two other large Rock-fish examined, weighing each about a 

 dozen pounds, one was free of parasites of all kinds, and in the other 

 there were only a few of the little crustacean, Ergasilus, adhering to 

 the gills; and within the abdominal cavity, adherent to the stomachy 

 closely coiled and encysted, a dozen nematoid worms, the Agamo- 

 nema capsularia, a common parasite of the shad and herring. Neither 

 of the fish contained a single Echinorhynchus, a remarkable cir- 

 cumstance, for he had never before examined a Rock-fish without 

 finding this parasite present. 



Louse of the Pelican. — Prof. Leidy remarked that the admirable- 

 monograph of E. Piaget, " Les Pediculines," a large work with sup- 

 plement, in 3 quarto volumes, illustrated, and published in Leyden 

 from 1880 to 1885, presented to night, had reminded him that he 

 had formerly made a communication to the Academy on an insect of 

 the kind, Avhich was remarkable on account of its living in the pouch 

 of the Pelican. A brief description of the louse, under the name of" 

 Menopon perale is given in the Proceedings 1878, p. 100. Mr. Piaget 

 describes two species of Menopon from Pelicans, M. titan, living on 

 PeUcanus onoci-otalus and M. consanguineum, which he observes ap- 

 pears by preference to infest the interior of the great pouch of P.. 

 erythrorhynchns. He remarks of the latter that it probably has some 

 relation with Menopon perale, and regrets the insufficient description 

 of this species for comparison. Prof. Leidy continued that M. Piaget's 

 figures of Menopon titan and M. consanguineiim appear so nearly 

 alike and resemble so closely M. perale that from his own judgment, 

 he would have regarded them as all of one species. In 1878 he had 

 prepared a more detailed description with figures o^ Menopon perale^ 

 intended for publication in one of the government reports, but as it 

 was not called for, it was forgotten until he was reminded of it by the 

 appearance of the great work of M. Piaget. Menopon perale was 

 named from specimens submitted to him by Prof. Wyman, who ob- 

 tained it from the pouch of Pelicaims trachyrhynchus, in Florida, and 

 others obtained by Dr. E. Coues, from the same bird, on the Red 

 River, near Pembina, Dakota. Dr. Coues in his " Birds of the 

 North West," U. S. Geol. Surv. 1874, 587, says of the White Pel- 

 ican : " I took a female in very poor flesh, with worn, harsh, plu- 

 mage, which was attributable to a disease of the pouch. On the 



