78 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxvii. 



graduiiUy diminishing- in size to the last pair, whereas the outer branches 

 g-radualh' increase in size. This is not true of /. thomj)soni/^ 



PHYLLODURUS ABDOMINALIS Stimpson. 



FhyJloduriiK abdominalis Stimpson, Journ. Bost. Soc. Nat. Hist., VI, 1857, p. 71.— 

 LocKiNGTON, Proc. Cal. Acad. Sci., VII, 1877, Pt. 1, p. 57; Ann. Mag. Nat. 

 Hist., 1878, pp. 299, 300.— Richardson, Proc. U. S. Nat. Miis., XXI, 1899, 



p. 868. 



LocaliUj. — Puget Sound; Tomales Bay, California, "on Upogebia 

 jmgettensU;-'' San Francisco Bay on Upogehia pugettensis. 



PSEUDIONE GIARDI Caiman. 



Pseudione giardi Calman, Ann. N. Y. Acad. Sci., XI, 1898, No. 13, pp. 274-281, 

 pi. XXXIV, fig. 5.— Richardson, Proc.U. S. Nat. Mus., XXI, 1899, p. 869. 



Locality. — Puget Sound, on Pagurus ocJiotensis (Brandt). 



PSEUDIONE GALACANTH.(E Hansen. 



Pseudione galacanthx Hansen, Bull. Mus. Coinp. Zool. Harvard College, XXXI, 

 1897, pp. 118-120, pi. V, fig. 22 *.— Richardson, Proc. U. S. Nat. Mus., 

 XXI, 1899, p. 869. 



Locality. — Gulf of California, in the branchial cavit}^ of Galacantha 

 diomedese var. parvispina Faxon; near Flattery Rocks, Washington, 

 parasitic on Munida quadrispina Benedict. (Collected by U. S. Fish 

 Commission steamer Albatross.) 



«The descriptions of the type species, lone thoracica (Montagu), are so unsatisfac- 

 tory and inadequate and so much at variance when compared that the only action 

 to take, under the circumstances, is to place the form described above tentatively in 

 the genus lone Latreille and to give it a new specific name. 



Montagu and Kossman describe the pleon of lone thoracica as composed of six seg- 

 ments, all of which are produced laterally into arborescent, branching lamellae. 

 Montagu in liis figure, however, represents but four segments, with five pairs of 

 branching lamellse. Milne Edwards, Bate and Westwood, and Giard and Bonnier 

 describe six segments, with only the first five produced into ramified appendages. 

 The appendages of the last segment are described as simple, recurved. 



Montagu mentions also six simple, recurved appendages, of which the last two are 

 larger than the rest. Kossman describes six jiairs of double-branched pleopods 

 (pleopodoiden) and also a single pair of simple, cylindrical uropoda (pleopoden). 

 Milne Edwards says that the first (appendages of the first five segments?) carry at 

 their base a little "ecaille" folded beneath, under the abdomen. Bate and West- 

 wood refer to the i)leopoda in the following way: "Several of the basal appendages 

 are, moreover, furnished at the base beneath with a small scale, lying beneath the 

 tail." Finally, Giard and Bonnier, characterize these appendages in this way: 

 "Rames des Pleopodes composes de six articles." 



The species herein described aa new seems close to lone cornuta Spence Bate. In 

 the original description of lone cornuta the pleopoda are simply described as "long 

 and fringed with arborescent branchia,'." Bate and Westwood mention the jointed 

 character of these appendages (pleural lamelhe), and give a much fuller description 

 of the species. 



