230 REPORT ON ZOOLOGY, MDCCCXLIII. 



united merely into a short tube for the siphons. The siphons separate, the 

 superior shorter, foot long, compressed; curved valve free, inequilateral 

 Two minute cardinal teeth, under the apex on the right, one on the left, 

 behind them a hollow for the internal ligament, two triangular lateral 

 teeth on the right. An external and internal ligament ; pallial impression 

 large. 



Mya semistriata, Hauley (Proc. p. 6), is defined from a single shell. 



Potomomya nimbosa, Hinds, from the Rio de la Plata, and ocreata, Hinds, 

 from fresh-water streams in Brazil. 



E. Forbes adds to the two already known species of Neeera, Gray, 

 two new ones, from the jEgean Sea, N. aticnuata, and abbreviata. (Proc. 

 p. 75.) 



Ib. is contained the description of 17 species of this genus by Hinds, 

 among which are included Corbttla costcllata, Desh., Anatina costata, Sow., 

 Mya rostrata, Chemn., and Telliiia cuspidata. 



A plate in the second Part of Philippi's work represents Solen, viz. Solen 

 abbreviates, Phil. (Solen vagina, Var. albr., Lam.), truncates, Sower., vagi- 

 noides, Lam., ititermedius, Koch (S. vagina, var. a, Lam.), Vagina, Linn., 

 and 8. marginatus, Koch, from Africa, which differs from Vagina by the 

 narrower and rounded posterior end. Three species are described by 

 Hauley (Proc. p. 101), S. pJiiIij)pinariim, from the Philippines, acinaces, and 

 cylimlracem, without assigned locality. 



f /tolas dilatata, Souleyet, from Manilla. (Rev. Zool. p. 176.) P. spathu- 

 lata, Desh. (Guerin, Mag. pi. 79), transversely laniellated, longitudinally 

 striated, smooth posteriorly, beaked anteriorly. Chili. 



Caillaud communicates, in Guerin's ' Magas.' pi. 69-71, 

 interesting observations on Gastrochena modiolma, which he 

 made at Malta. The animal is furnished with a calcareous 

 tube, which internally for about one third of its length 

 presents two ridges, which not being united separate the 

 siphons imperfectly. The very minute animals bore ex- 

 tremely fine holes in the stone, of which holes two are 

 always situated close together, though entirely distinct. 

 The author asserts that the animal, before reaching its full 

 development, must possess the form of a thread-like worm, 

 which penetrates to a depth of even 20 millimetres, accord- 

 ing to the degree of hardness of the stone, then makes a 

 turn, and thus bores a second hole parallel to the former 

 until it has effected a second opening. The author has 

 met with instances in which the second portion of the 



