Sowevhy's Genera of Shells. 129 



species of a new Tipulidous genus, differing from Tipula in liaving 

 only twelve joints in the antennae and a few scattered bristles 

 upon them, instead of thirteen joints ornamented with whorls of 

 hair; from Limnobia in the very great length of the terminal joint 

 of the palpi and the long cylindric joints of the antennas; and from 

 both in the absence of the third disroidal cell, and in the extra- 

 ordinary length of the basal joints of the tarsi, which are all very 

 much longer than the tibiae. 



The sixteenth number contains 1. Acilius cinereus, now first 

 noticed as British, and distinguished from the common A. sul- 

 catus, by being smaller and darker, with the hinder thighs en- 

 tirely pale and not black at their base : 2. Eupithecia linariatay 

 the beautiful pug of the collectors, a new genus comprising the 

 species of Mr. Haworth's section, Abbreviatce : 3. Hylotoma 

 Siephensii, Leach : and 4. Helcomyza ustulaia, Meigen, MSS., a 

 genus nearly allied to Scatophaga^ from which it may however be 

 at once distinguished by the tibiae being only woolly without any 

 bristles, and by the basal joint of the posterior tarsus not being 

 longer than the second, rather compressed, and a little bent. 



The Genera of Recent and Fossil Shells. By G. B. Sowerby, 

 F.L.S. with original Plates, by J. D C. Soweuby, F.L.S. 

 No. XXV. 



The Genera illustrated in this number are five; Sanguinolaria, 

 Coronula, Saxicava, Buccinum, and Nassa. The former of these 

 does not correspond precisely with the genus as established by 

 Lamarck, the S. occidens and rugosa of that great Conchologist, 

 being regarded as referable rather to Psammobia, while his Sole- 

 nesy violaceus and rostratus, are included in the present Sanguino- 

 laria, of which S. rosea may be taken as the type. The species 

 figured are S. rosea and iS*. Diphos, the latter being the Solen 

 Biphos of Chemnitr, and Solen rostratus of Lamarck. The genus 

 Saxicava is particularly deserving of attention from the extremely 

 variable appearance of its typical species, which is at once the Solen 

 minutus of Chemnitz and Montagu, Hiatella arctica of Daudin, 



Voi-. II. I 



