80 Miscellaneous. 



nent, is separated from the lateral ones on each side by a deep chan- 

 nel, and gradually and regularly tapers to its termination, which is 

 near the end of the body. The lateral lobes are rounded. The 

 costal arches of the abdomen have a furrow scooped out of their up- 

 per surface, and their outward extremities terminate in obtuse points, 

 between which there is a raised line. The caudal arches are not 

 grooved, but there is a faint impressed line running along their up- 

 per surface, which is slightly bifurcated at their termination. 



This beautiful and highly interesting trilobite was found by Mr. 

 George L. Le Row, of Poughkeepsie, N. Y., to whose kindness I 

 owe this opportunity of describing it. The specific name is given in 

 compliment to the discoverer. There is a strong analogy in some 

 leading particulars between this species and our C. Diops. Pro- 

 fessor Dalman's C. concinna represented on his first plate, fig. 5, a, b, 

 and c, comes very near it, but there are many marked differences be- 

 tween them. It was found imbedded in a layer of soft argillite, 

 slightly ferruginous, and of such is the fossil composed. The strata 

 in which it was found was filled with Orthocer<B and numerous other 

 fossils. Immediately under this layer is another of argillite, of 

 harder texture and darker colour, and free from petrifactions. — Dr. 

 Green, in Sillimari 's American Journal of Science, No. 2. Jan. 1838. 



FOSSIL ARGONAUTA. 



Mr. Sismonda, jun., of Turin, has discovered near Coningliano^ 

 in the blue marls of the super-cretaceous deposit, the Argonauta 

 Argo, Linn., a genus which does not appear to have been hitherto 

 found in a fossil state. — Ann. des Sci. Nat., Aout 1837. 



GENERATION OF PTEROPTUS VESPERTILIONIS. 



Chr. L. Nitsch has lately ascertained that the Pteroptus vesper- 

 tilionis, Dufour, (Gamasus vespertilionis, Lat.) is by no means ovipa- 

 rous, (as Goze supposed,) but viviparous ; that it bears but one young 

 at a time ; that this comes into the world with eight feet, but the 

 younger foetus or embryo has only six feet, and therefore undergoes 

 a metamorphosis in the body of the mother, which in many other, 

 also parasitical genera of Acari, first takes place after the birth, 

 or after quitting the egg. The six-footed embryos are soft, milky 

 white, and quite without hair. The feet and palpi are non-articu- 

 lated, the former terminating conically and abruptly, without any 

 claws. The feet and palpi in the 8 -footed foetus exhibit evident ar- 

 ticulations, amounting in the former to seven ; the claws are present. 

 The colour is yellowish white. — Wiegmann's Archiv, Part IV. 1837. 



