May 4, 1SS3.] 



SCIENCE. 



sn 



MoUusks, 



Large American pearls. — Some remarkably large 

 pearls liave been obiaiiieil, during the last fisliing- 

 season, at the fishery near La Paz, in the Gulf of 

 Califdi-nia. One found in December, — the largest on 

 record from this region, — weighing 75 carats, sold 

 on the spot for §14,0Ull, and is considered to be worth 

 much more. Another very perfect one, of 47 carats, 

 is valued at S"i,OUO; anil a third, at $3,000. It is 

 many years since such good fortune lias attended 

 the (livers of this region, though the product of pearls 

 of luodeiatesize has been tolerably constant. — {j>fec. 

 Jiiianccro, Jan., 1SS3. ) w. ii. D. [788 



Ottav?a Unioiiidae. — The researches of Mr. F. R. 

 Latchford among the fresh-water mollusUs of the 

 vicinity of Ottawa have been fruitful of results. In 

 'Notes on Ottawa Uuioniilae,' ho mentions fourteen 

 species of the genus Unio, of which otie (U. borealis 

 Gray) is new, and apparently valid. There are also . 

 three species of Margaritana, ami ten of Anodonta. 

 Previously, only twelve species altogether luul been 

 recorded from this vicinity. The paper is full of in- 

 teresting lii'>graphical details in regard to (he species 

 enuinorateil, and their varieties. The author notes 

 the asymmetry of the embryos of Unio in Anodoiita 

 fluviatilis, Unio luteolus, and U. borealis, and infers 

 it for Unionidae in general, tliongh they have been 

 described as jierfectly symmetrical." A mite found in 

 the gills of A. fragilis, and placed in the hands of 

 Mr. Tyrrell for investigation, is as large as a pellet 

 of buckshot. It appears that the lumbermen on the 

 Chaudicre eat these imdlusks, and obtain Ihem in an 

 ingenious manner. Birch brushwooil, tips down, is 

 attached to the raft so as to drag gently over tlie bot- 

 tom when in the shallows. The open bivalves feel 

 the twigs passing over, close the valves on thein, aiul 

 hold fast. At intervals the brush is lifted, and the 

 adhering ' clams-' are picked off. — ( Tnuis. Ott. field 

 nat. club, no. o.) w. ii. d. [789 



Fossils of the Rizzolo clays. — Seguenza has 

 just i-sued a brochure in regard to the cTay ileposits 

 of Uizzolo, lUTnince of Syracuse, Sicily, with lists of 

 the fossil niollusks found in them, which comprise 

 two pti-ropods, iifiy-live gasteropods, and si.xty-eight 

 lainellibrauchs, many of which still live in adjacent 

 waters. The deposit is considered by the author to 

 be quaternary, ami derives its interest particularly 

 from the fact, that remains of the living African 

 elephant (E. afiicanus Blum.) have been discovered 

 in it, raising interesting questions as to the former 

 range of that mammal. To the discussion of this 

 branch of the questicm, and of the identity of the 

 species, the paper is chiefly devoted. — ^v. u. D. [790 



Devonian myriapods. — An interesting discovery 

 has been made by B. N. Peach, in the lower old red 

 sandstone of Scotland, of myriapods in rocks older 

 than the carboniferous series, the lowest that have 

 before this yielded them. Two species are described 

 and excellently figured, one of which has long been 

 known, and supposed to be a Crustacean, having been 

 described by Page nndcr the name of Kampecaris 

 forfarensis. Tlie~y are of small size, and differ con- 

 siderably from each other. Kampecaris is cylindri- 

 cal, scarcely tapers at the head end, and is coinposed 

 of numerous sub-equal alternately larger and smaller 

 somites, each bearing a pair of legs. Archidesmus is 

 depressed, fusiform, witli altermuely very unequally 

 larger and smaller somites, each bearing a pair of 

 'six or seven jointed' spinous legs (none are shown 

 In the figures attached to the smaller, intercalary 



somites). It will be seen that they differ consider- 

 ably from the known carboniferous myriapods. — 

 (Proc. roy. phys. sac. Kdinb., vii. 177, pi.) [791 



Dermal appendages of Polyxenus. — The differ- 

 ent forms of liairs iu P. fascicularis are 

 described and figured by Scudder; thdse 

 upon the body-joints, f(, h, varying from ' 

 club-shaped sjjines, furnished with several 

 rows of flattened teeth, to sabre-shaped 

 spines, seirate on the conve.x side. The 

 posterior extremity of the body is provided 

 with a pair of cylindrical fascicles, resem- 

 bling those of the larva of Anilirenus, but 

 coinposed of very curiously-formed bris- 

 tles, c, shaped like an elongated fish-hook, 

 the shaft gently curved, and the tip re- 

 curved and apically barbed. The shaft 

 is armed wiili delicate spinules, and the 

 crook furnished on the concave side with 

 a few spatulate, drooping appendages. 

 These aiipendages are also figured, raUier 

 iudely, by Packard in the Amer. nal. for 

 March. — [Proc. Bost. soc. nat. Iiist, xxii. G7.) [792 



Iiiseots. 



The American species of s-wallo-w-tail butter- 

 flies.— As the result of the stiuly of a large series of 

 forms partly collected by himself in Washington Ter- 

 ritory east of the Cascade Mountains, — a hitherto 

 unexplored region, — Dr. Hagen concludes that P. 

 Zolieaon, oregouius, and Aliaskn, are all specifically 

 inseparable from the old-workl P. Machaon, the range 

 of variation in which he also discusses. He also 

 unites P. Kutnlus and Euryiuedun, and considers 

 them a western form of P. Turn us. — (I'apilio, ii. 149.) 

 W. II. Edwards vigorously combats this view, so far 

 as the flrst series is concerned [Ibid., iii. 4j, pi.). [793 



"Wisconsin Lepidoptera. — The geological sur- 

 vey |iublislies a catalogue of Wisconsin Lcjiidoptera 

 by Hoy, long know-n as an enthusiastic collector in 

 that state. The title is a misnomer ; for, besides the 

 butterflies (99 sp.) and hawk-moths (.j2 sp. ), the 

 author only eiinmcrates the Bombyeidae (7o sp. ) and 

 Ge(uuctiidac (1(;9 sp. ); the Noctuidae (388 sp. ) being 

 oddly placed iu a separate list, and other groups 

 wlioily omit led. ^'ot the slightest notes are appended, 

 except in the first two gnaips, where an iiulication 

 of the abundance of the sjiecies, in a single word, is 

 usually given. \Vith the exception of aii occasional 

 straggler from the soutli, the list contains nothing 

 noteworthy.— (Z^c;;. £/eo;. surw. IKiSC, i.) [794 



Geographical origin of Worth-American 

 Sphiugidae. — Tliree proximate sources are foimd 

 by Grote for our Sphingid fauna, which consists of 

 abovrt (13 species. Omitting Si)hinx, wliicli the au- 

 thor claims to belong to an older period of separation, 

 10 genera (32 sp.) are considered as descendants of 

 a circumpolar pre-ulacial fauna; 11 genera (26 sp.), 

 accessions from the tropics; and 14 genera (20 sp.), 

 of North-American origin peculiar to the continent. 

 All the species of a genus (cxcl. Sphinx) are thus 

 seen to have a common geographic origin. "The 

 decisive element in our fauna does not come from the 

 old world." — (Amer. jourii. sc, March.) [795 



VERTEBRATES. 

 (.Pliyniology.) 

 Influence of the centre of deglutition on 

 that of respiration. — Steiner calls attention to 

 some generally overlooked researches which show 

 that an act of swallowing is usually accompanied by 

 a more or less marked respiration, and himself adds 



