492 Zoology. 



the phosphorescence in our seas to be exhibited with the same characters every year 

 during the summer season, but it was interrupted in the waters of the channel 

 (De la Manche) when the cholera morbus prevailed at Havre and its vicinity in 

 the month, of May, June, and July 1834. * Several naturalists of the French 

 capital, who are in the habit of visiting our harbour from season to season, and 

 who had been observant of the phenomena, confirm this remarkable fact ; and 

 the whole city is witness to the sudden and very general mortality of the fishes 

 kept in our preserves of brackish water which then occurred. All the eels and 

 flat fishes came to the margins and died. M. Surivay examined with the microscope 

 some drops of the water become a little putrid, and he ascertained that its slight 

 blood-tinted colour depended on the increase of different kinds of infusory ani- 

 malcules. 



The diffused phosphorescence observable in our seas during the summer, M. 

 Surivay attributes to the prevalence of a minute species of medusa (Noctiluca 

 miliaris,] which he has described and figured in Guerin's Mag. de Zoologie. 



Parmacella, Cuvier — MM. Webb and Vanbeneden have attentively examined 

 the American mollusca reputed to belong to this genus in the rich collection of 

 the late Baron de Ferussac, and the result is the establishment of a new genus 

 (Peltella) for their reception, the organic differences between them and those of 

 the old continent being so considerable as to justify their separation. This divi- 

 sion besides has the advantage of fixing in a precise manner the geographical dis - 

 tribution of the two genera. The Parmacella; appear to belong more particularly 

 to Northern Africa, one species only having been met with at the western extre- 

 mity of Europe, and in one of the warmest regions of the Iberian Peninsula. We 

 may then presume, that when the Limacidce of the north of Africa are better 

 known, the group to which they (the Parmacella?) belong will present a series of 

 species similarly conformed, and replacing in those climates the slugs of our tem- 

 perate regions. The European species is minutely described and figured in a late 

 No. of Guerin's Mag. de Zoologie. It was found on the hills of Alcantara be- 

 hind Lisbon, feeding on the young shoots of Cochlearia acaulis, and is charac- 

 terized as follows : 



Parmacella Valenciennii, corpore toto fulvo, reticulatim rugoso ; concha scu- 

 tello obvoluta, tenui, diaphana, fragilissima ; spirse rudimento instructa, basi mo- 

 taria amditu sinuata Webb and Vanbeneden in Mag. de Zoologie. 



On the sexes of some Crustaceans — It is to be observed that, in regard of sex, 

 the Cancroidea differ not only in being male and female, but there are also bar- 

 ren or spurious females, of which the broadly-trigonate abdomen is narrower than 

 in genuine females, although broader than in the males. These are not to be con- 

 founded with young females whose abdomen, as in the Majacese, is flatter than in 

 the adults, for of several species there are both barren and fruitful individuals of 

 the same age. The Cancroidea and Matuto'idea are hitherto the only families in 

 which these sterile females have been noticed. Portunus (Neptunus) pelagicus, 

 sanguinolentus ; (Amphitote) gladiator, hastatoides ; (Charybdis) miles, 6-den- 

 tatus; (Thalamita) truncatus ; Ocypode (Macrophthalmus) japonica ; (Helice) 

 tridens ; Grapsus (Erischeir) japonicus ; (Grapsus) marmoratus have afforded 



" The exact year, as well as the name of the author's place of residence, is omit- 

 ted in the essay from which this notice is extracted. 



