OF ARTS AND SCIENCES. 61 



Pedes paris secundi grandes, articulo penultimo ad apicem spinigero, 

 ultimo crassissimo, superficie terminali oblonga, squamata, squamulis 

 spinula armatis. 



Long. -J". — Hah. in corpus specie! Musteli (Squalorum familiae). — 

 — Lect. ad urbem " Rio de Janeiro." 



Tribus 4. NYMPHACEA. 



Genus ASTRIDIUM. (Dana.) 



Pycnogono affinis. Caput duobus maxillipedibus subtus instructum 

 parvulis, debilibus, apice obtusis, non prehensilibus. Pedes octo un- 

 guiculo confecti. Aldomen perbrevis. 



AsTRiDiuM ORiENTALE. — Ccphalothorax stellatus, segmentis medio 

 connatis, deinde liberis. Abdomen breve, postice angustius, obtusum. 

 Truncus buccalis oblongus, subcylindricus, corpore vix brevior. Seg- 

 mentum corporis primum antice non transversum, postice angustius et 

 deinde utrinque longe productum instar rami brevis,* et pedes anticos 

 gerens. Maxillipedes parvuli, obsolete 3-articulati, obtusi. Pedes cras- 

 siusculi, articulo primo vix oblongo, sequentibus sex subaequis, tertio 

 paulo breviore. 



Long. I". — Hah. in mari " Sulu." — Lect. die 11 Feb., 1842. 



Mr. Borden, from the committee to whom was referred the 

 paper of Mr. M. Conant, describing his " Solar Index," pre- 

 sented a report, entering fully into the investigation of the 

 principles of the instrument. The conclusion which the com- 

 mittee has arrived at is, that, although the " Solar Index " is 

 not susceptible of sufficient accuracy to be used with advan- 

 tage for nice scientific purposes, yet, as it can be managed 

 with great facility, it may frequently be found valuable to the 

 surveyor and engineer in making experimental surveys, run- 

 ning preliminary lines, &c., for the purpose of learning the 

 character of the topography of a country, and of acquiring, ap- 

 proximately at least, a knowledge of the relative situation of 

 places. 



* Haec pars postica segmenti prinii segmentum corporis secundum verc est, 

 quamvis articulations verA non sejuncta. 



