49 



milir inner edge black dentate, outer one hairy. 

 Hra tooth on the outer edge near the ape* 

 The other segments rounded, pilose. 



First segment of the tail broad, and articula- 

 ted at right angles to the carapace. About 

 Srirt principal tubercles on the superior edge, 

 Sve P on the inferior, and one large one near the 



middle of the plate, on each side ol i 

 San line. Those on the superior edge m pairs. 

 A cavity near each end of the segment and 

 two deep, well defined, depressions about half an 

 nVn n/ diameter, midway toward the .middle 

 or the plate. The remaining- segments of th< 

 t if are'divided longitudinally by articu 

 the outer one on earn side being about hall an 

 inoh from tha edge. The inner articulations d»- 

 v^thetluiint-^invesuo.-Huai.-oi-,^ 

 Urns forming eleven quadnlatera) plab 

 J ';,,',! angles of the 3d, 4th and ■ i 

 r Scated,and the spaces filled with sern 

 2S Between the 3d, 4th 5th and 61 

 £ al segments, are interarticular plates. Al«l 

 Kseptatesare largely tuberculous and cover- 

 S with minute spines. The tail margins .are 

 ™ S entedbyl2orl5 S errature S ,eachotwh 

 K„ a separate plate. A« the shell grows u 



these coalesce with each other and wit 



Sternal adjoining plate, so that but three Ion 

 Sal sections remain. Thesegmentec 

 in"the tail are articulated by means of a 

 the epidermic^nembrane, and the entire ar, 

 mentis calcula - pliability to itebro 



Surface, so that it shalUhe more compteUyp 



tect the large mass oi ova which the a 



appendages support. 



Hand robust covered with a tuft of hair : 



The specimen from which this description was 

 taken, was caught near the Farallones, in about 

 thirty fathoms water, it was presented to the 

 Academy by S. M. Bowman, Esq. 



Dr. Winslowread the following paper on the 

 ! of Tides, Earthquakes, Rising of Con- 



aents, . nd Variations of Magnetic force. 



■ 



largeroundedteethoiit.be, outer edge of the . 

 cers three dentations on the inner side, and 

 basal tubercle across the finger. Left hand i such 

 smaller than the right. Arm sub-quadrate with 

 a triangular crest projecting ft «ght angle 8 to 

 the inner side, having conical tubercles , « , ,ti 

 ,,!,,■< internal condyle with a broad, bidentatc, 

 Curved spine. All .he legs are covered with 

 conical tubercles studded with short acu 



,,, 1;!1 . tuberosities on the lower side of the 

 Lterandon the haunches. All the 

 quadrangular. The second third and fourth leg, 

 miate by short claws, the arsal joint c 

 .ringlymus. so thai tlie feel caubedn ctei 

 fcrdsoi b: ,ards. Fifth pair of Jegs r, 

 .limentaiy, inclosed in the shell, rounded al tin 

 extremity and thickly set with bristles. 



Ground c lor dl tl ill vermilion, gruuul 

 all d spines generallj deepblueaud purple. lh« 

 enti re shell is covered with mmute bristles. 



Length of largest specimens 1 10 inches; grj 

 at transverse &m ter in- , inches. Lwgtho 

 pairoi legs 9 inches. Weight of th< ani- 

 mal 6% lbs. 



CAUSES OF TIDES, EARTHQUAKES, RISING OF 

 TISBNTS, AND VAKIATIONS OF MAGNETIC F01 



By C. F. Winslow, M.D. 



, scussion in th( Boston Society oi 

 Natural History on the paper of M. Alexis Fer- 

 ry Prof, in the 'Faculty of Sciences of Dijon, o 

 ■ ( 'atu w which may exist between 

 the frePHcncu of eart 



useofei I quakes,; ce 



, der on I i "< i P» °) ' 



:■!!.:■ has i -■ r 



, | ; ,,, r. ti encesofl 

 i . he same subject; I as ti 

 a my Cosmography, 

 . ce. cover ■■ mu, i In g ' P™ 1 **^ 

 . cesa nn Ititude of phci i I " I **** 



s of Mr. Ferry and Mr. d ' «"J no 



: eivea 



,„ aream- 



.., rtmeul of s n. . Hie physics of tii. 



its infancy and is n ' d ■" ' : " 



bservedin notin] 



: « ■ ■ Pendulum. 

 ........; | mi D , ingsm mountains, 



. „d mines, independent o admag- 



. ptenomenain connexion witl e th tiakes 



rtions whether from known 



J re or at the bottom of the sea, ahd indeed in 



physical research and sta- 



perfeel observed should be 



wM ml i spianatory comment, anclatiast 



,,. ; basis willl itablishedon whichto 



V . :. . i will i mbrace 



cr 



upa truthful structure I 



Kent re and perfect historj and.! 



", /r.-.th 1- 1..-H-V,.. .-vt-n oi" 11m; i ,.:v. rsc 



j u U. he connexion between I 



and bet* ■ 



... ., i8 so intimate thai 



, ester, e nd nervations 



and a! 



in ■ mos 



, ■'''', ,„ii, ,„,..■ i,! i ir.-xi..,i v.-illi. ai»l 



K Salts useful to science and mankind. 



