284 



covered Avith tliick yelloTvisli-wliite. leathery scales, the largest meas- 

 lu'iug over one incli in diameter, and over one-tentli inch in thickness. 

 He was literally covered with scales like a fish. Upon cross-sectioning 

 one of the scales itch-mites were fonnd in abundance, and with proper 

 treatment the ndtes were exterminated and the skin regained its nor- 

 mal character. An interesting calculation of the number of mites 

 present on the host was made by Dr. Hessler. The estimate resulted 

 as follows: Egg-cases and eggs 7.004.000: mites. 2.009.000. It seemed 

 probable, however, that fi^om one-half to three-fourths of the eggs had 

 already hatched, while a comparatively small proportion of the mites 

 were liA-ing at the time when the scales became detached. TTe are in- 

 debted to Dr. Hessler for some very fine microscopic mounts of cross- 

 sections of the scales differentially stained with picro-carndne. which 

 resulted in the epithelium taking the red color, the mites the yellow 

 color, while the eggs remained unstained. 



0>- HAEVi:ST SPIDEKS. 



Under thf title '"The Striped Harvest Spider" Dr. C. M. TVeed gives 

 an interesting study of specific variation in the December number of 

 the American Xaturalist. showing that Plialangium vittatum Say. and 

 P. dorsatum Say. are inseparable upon structural details. After the 

 study of nearly a thousand specimens Dr. TTeed concludes that we 

 have to deal here with a single very variable species in which natural 

 selection has increased the size of the body and length of the legs in 

 the south and shortened them in the north. The eggs of this species 

 probably hibernate and the young of the northern form hatch in May 

 and become mature the latter part of June or July. The young pre- 

 fer the shelter of the gTass, low herbage, and nibbish piles, and in Hli- 

 nois are common ui>on com, where, as Dr. Weed has surmised, they 

 probably live upon the numerous smaU insects drowned in the moisture 

 contained in the bases of the unfolding leaves as well as upon plant- 

 lice. The article is illustrated by one page plate. 



A CrTtlOUS PAEASITE OF THE PELICAX. 



Our correspondent. 3Ir. Alvah A. Eaton, of Eiverdale. Cahf.. recently 

 sent us specimens of lice which he had taken from the gidar sac of the 

 TVTiite Pelican, the accomj^anying note reading. ••Bird killed this morn- 

 ing at 6 :30. Laid in water with head under till 12 :30. Lice alive and 

 lively at the end of that time." The specimens were determined for us^ 

 by Prof. Osborn as ^lenopon consanguineum Piaget. He writes us con- 

 cerning the species as follows : 



I have seen it a. nninber of Times collected at diJierenT localities, and hare taken 

 niimbers of them, from tT\*o pelicans brought here ahont rwo vears ago. I formerly 

 referred the specimens to M. titan, vrixh. which it is very closely related, hut Piaget 

 has seen fit to erect for it a new species and the characters are probably of sirfficient 

 importance to justify his action. 



