332 Dr. A. S. Packard on iieiv North- American PhyUojwda. 



lower forms of both animal and vegetable life, since in propor- 

 tion as this is the case he will avoid such egregious blunders 

 as those above mentioned. 



Indeed this observation holds good not only with the Spon- 

 giadse, but with all the lower divisions of animal and vegetable 

 life. 



If a man be not generally acquainted with them, besides 

 being a general histologist, it may be inferred that his writings 

 on them will be more or less inaccurate, and thus fail to be of 

 any scientific value; they will be more for show than for 

 usefulness or truthfulness, and, worst of all, occasion a grievous 

 loss of time to the hond fide student. 



I am, my dear Dr. Francis, 



Very sincerely yours, 



Henry J. Carter. 



" The Cottage," Budleigh-Salterton, Devon. 

 Oct. 18, 1871. 



XLII. — Preliminary Notice of New North- American Phyllo- 

 poda. By A. S. Packard, jun., M.D.* 



The following brief descriptions are extracted from a mono- 

 graphical notice of our Phyllopod Crustacea, which, with the 

 exception of the Branchipodidge, so thoroughly investigated by 

 Prof. Verrill, have been sadly neglected. It will be noticed 

 that North America is rich in the species of Apus, more so than 

 any other quarter of the globe so far as yet known. It is a 

 little singular that no species has yet occurred east of the Mis- 

 sissipi river. The species of Limnadiadge are probably more 

 abundant than naturalists are aware of; and the attention of col- 

 lectors of shells is called to these Cyclas-\ik.e-she\\ed Crustacea, 

 whose shells may not unfrequently be mistaken and passed by 

 as simply species of Cyclas. For the privilege of studying the 

 species of Apus I am indebted to Dr. William Stimpson, who 

 has lent me the specimens placed on deposit in the Chicago 

 Academy of Sciences by tlie Smithsonian Institution, and to 

 Prof. A. E. Verrill, who has contributed the specimens in the 

 Yale Museum ; while the Museum of Comparative Zoology at 

 Cambridge has contributed a new Apus from Northern India ; 

 and for the Limnadiads my acknowledgments are due to Mr. 

 G. W. Belfrage, an industrious collector, and Prof. E. S. Morse, 

 who have given several species to the Peabody Academy of 

 Science. 



* From the ' American Journal of Science and Arts,' vol. ii, August 

 1871. Communicated by the Author. 



