136 PHILOSOPHICAL TRANSACTIONS. [aNNO 1771. 



t 



Mr. M. has observed that they lay eggs, but this does not prevent their being 

 likewise viviparous: he has seen other species of monoculi, some of which had 

 their ovaria full of eggs, and others of little live insects, which at times they 

 hatched, and at others put down in the shell. 



The sordid species is the most commonly met with ; we find it all the year, 

 even in the time of frost, from under which Mr. M. has often drawn it. It is 

 found in all pure waters, and even in the little ditches which are exposed to be 

 overflowed by the sea. He has preserved it from May to November, full of life 

 and motion, in a glass of water, which he did not renew the whole time. The 

 smooth white insect lives at the bottom of marshes, and pools, in which the 

 conferva grows. 



The knowledge of these insects has been almost entirely neglected, though 

 in reality very interesting; not to speak of their wonderful make, the difference 

 of their motion, and their singular mode of copulation, are worthy of our 

 inquiries. Let it be sufficient to say, that we swallow them and their shells, 

 either living or dead, both in our victuals and drink; so that Mr. H. would not be 

 surprized, if some time or other they were found in our intestines, or in 

 those of beasts, and several of our diseases attributed to them. 



Explanation of the Bivalve Insect pi. iii — Fig. 3. The smooth insect as it is naturally. Fig. 4. The 

 same, seen through the magnifier. Fig. 5. The same magnified by the microscope. The transparent 

 shell shows the inhabitant lying at its full length; with the antennx, legs and tail, out of the 

 valves; a the edges of the two valves; b the antennae; c the eye; d the head; e the ovaria; f the 

 fore legs; g the hind legs; h the tail; i the fore part of the breast, where the beards and mouth 

 •replaced; k the belly. Fig. 6". The sordid shell of its natural size. Fig. 7. The same, as seen 

 through the glass. Fig. 8. The same, with the shell a little opened,and more magnified, a The 

 rough shell; b the oblique stripe; c the antennae; d the fore legs; e the hind legs; f the 

 mouth and joints; g the tail. Fig. 9- The same, with the shell shut. 



XXX. Of a Singular Fish, from the South Seas. By the Rev. Michael Ti/son, 



p. 247. 

 This curious fish, preserved in spirits, was brought, by Commodore Byron, 

 from the new-discovered islands in the South Sea. As there is the greatest 

 reason to believe that it has never been figured or described by any author, and 

 indeed never before seen in Europe, Mr. T. sends the following description and 

 drawing of it, fig. 10, pi. 3. He could not count the branchiostegous rays, 

 without really injuring the specimen, but there is no doubt of its being one of 

 the perca genus of Linnaeus. It is called by the Commodore the zebra fish, 

 not knowing its proper name. The drawing is exactly measured from the real 

 fish, and is in every part of the same size. 



