April 17, 1879] 



NATURE 



557 



the lower teeth interlock in an exact manner with the 

 upper. The hold or grip of a wolf fish must therefore 

 be of a tenacious kind. Behind these incisor teeth, both 

 above and below, are seen a few small teeth, destined by 

 the ordinary laws of dental succession in the fish-group 

 to replace the incisors in case of injury or loss. These 

 front teeth are firmly anchylosed to the bones on which 

 they are borne. 



More interesting are the palatal teeth, and the corre- 

 sponding teeth of the lower jaw. To these latter, the 

 name of "molars" or "grinders" is frequently applied. 

 Close to the front of the upper jaw we find a series of 

 three tooth-masses, one central and two lateral, arranged 

 in diverging fashion. The central and largest mass re- 

 sembles the tuberculate molar of a bear in form, and is 

 composed of four firmly united segments, each segment in 

 turn consisting of two pieces. The lateral teeth of the 

 palate, similarly consist of a double series of firmly united 

 segments, but in each of these lateral pieces the outer row 

 of pieces is composed of sharp-pointed segments, resem- 

 bling miniature incisors. The accompanying diagram 

 will afford an idea of these curious palatal arrangements : 



A is the central piece ; B and C are the lateral pieces, 

 the outer teeth of which (;>/) consist of pointed and 

 incisor-like pieces. It follows from this description that 

 the sea wolf possesses in its mouth an apparatus not 

 merely adapted for tearing its food but for exercising a 

 triturating and bruising action as well. 



No less characteristic are the dental arrangements of the 

 lower jaw. In the front of this jaw are four incisor teeth, each 

 fully three-quarters of an inch in length ; whilst two smaller 

 incisors exist as already mentioned, one at each side of the 

 larger series. Behind these incisors are the rudiments of 

 succeeding teeth, and these rudimentary teeth gradually 

 merge into the main dental arrangement of the lower jaw, 

 which consists of a prominent row of blunt teeth anchy- 

 losed to form a common mass, and partially forming a 

 double row on each side of the jaw. Section of the jaw 

 shows that the teeth are imbedded in a common groove, 

 and that complete and thorough ossification of the various 

 dental pieces renders the whole apparatus compact and 

 solid. The arrangement seen in the mouth of the wolf 

 dsh suggests the idea of the high specialisation of this 

 type of fish, as indicated by the development of the dental 

 apparatus. In none of the near neighbours of this fish 

 have we at all a near approach to the perfection of teeth 

 thus exhibited ; and in respect of its complexity and dif- 

 ferentiation of type, we may well be inclined to lend 

 some countenance to the idea of the independent origin 

 in widely removed fishes of structures seen in still greater 



perfection in such widely-removed fishes as the Elasmo- 

 branchiate Skates, Rays, and Cestracion. 



The stomach of the specimen I dissected was greatly dis- 

 tended, and contained fully four ounces of digestive debris, 

 consisting chiefly of disintegrated Ophiuroids, spider-crabs, 

 broken shells, shrimps and prawns, along with sand and 

 small gravel. The pyloric aperture was firmly contracted 

 and the collection of matter in the stomach clearly pointed 

 to some obstruction of the digestive canal as the cause of 

 death. It was also instructive to find that close to the 

 vent the rectum was largely distended with broken pieces 

 of shells and fine gravel. These matters, along with those 

 in the stomach, had evidently been intussuscepted before 

 the arrival of the fish in the aquarium and probably caused 

 death by the irritation consequent on their non-removal 

 by digestion. Andrew Wilson 



THE ETNA OBSERVATORY 



T T will be within the recollection of some of our readers 

 ■*• that in September, 1876, Prof. Tacchini, of Palermo, 

 communicated to the Accademia Gioenia of Catania a 

 letter, " Sulla Convenienza ed utilita di erigere suU' Etna 

 una Stazione astro nomico-meteorologica " {vide Nature, 

 vol. XV. p. 262). This letter was published in the Atti of 

 the Academy, and afterwards appeared in the form of a 

 quarto pamphlet with ground-plan and elevation of the 

 proposed building. The project was at once taken into 

 consideration both by the Italian Government and by the 

 Municipahty of Catania ; plans were prepared, money 

 was voted, and it was confidently believed that the ob- 

 servatory would be commenced in July, 1878. Owing^ 

 however, to certain delays, this was found to be imprac- 

 ticable, and the commencement was postponed till June, 

 1879. There is every reason to believe that the build- 

 ing wiU be erected and the instruments in working order 

 by the end of this year. The cost will be borne by the 

 Government, the Municipality of Catania, and the Pro- 

 vince of Catania. Merz, of Munich, has offered to con- 

 struct a 12-inch lens for the great refractor, at the price 

 of a lo-inch lens, and the enterprise has received encou- 

 ragement and support from various soiu-ces both at home 

 and abroad. 



The observatory will be erected at the Casa degl' Inglesi, 

 9,652 feet above the level of the sea. At the present time 

 the Casa is an oblong building constructed of blocks of 

 lava, and containing three rooms (^oide the accompanying 

 plan). It was built by the English when they occupied 

 Sicily in 181 1, and has since been used by those who 

 ascend the mountain as sleeping quarters. A few years 

 ago it had fallen into decay owing to the accumulation of 

 snow in winter and to other causes, but it was put into 

 complete repair in 1862 on the occasion of the visit of the 

 present King of Italy. The observatory will be the 

 property of the University of Catania, and will indeed be 

 a kind of offshoot of the BelUni Observatory of Catania. 

 It is to be devoted not only to astronomical and spectro- 

 scopic observations, but it will also be furnished with a 

 complete set of meteorological and seismological instru- 

 ments. Between the Etna Obsen^atory and Catania 

 three or four meteorological stations will be established 

 at different elevations, as at Nicolosi, and the Casa del 

 Bosco, and obsen'ations will be made at the same hour 

 daily at each of these stations, at Catania, and at the Etna 

 Observatory. 



The Merz lens of 12 inches diameter, has a focal 

 distance of 5J metres. The telescope and clock-work 

 movement are in course of construction by Signor 

 Carignata, the mechanician of the Padua Obser\'atory, 

 who constructed the instruments which were employed by 

 the Italian astronomers who went to India to observe the 

 transit of Venus in 1874. The ob5er\-atory will only be 

 inhabited during the months of June, July, August, and 

 September, and the large lens will then be transported 



