ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 595 



L. adpressa, should be changed. We would also suggest a comparison 

 of L. Sturii Ess. and L. formosa Sey. with L. decorata of Ess., and 

 L. elegantissima Sey., mitrata Sey., and thiara Sey. with varieties of 

 Cribrillina radiata Moll. 



As examples of cases where species are considered to occur only 

 fossil, but are living in the Mediterranean, we may mention Lepralia 

 eximia Sey. (which is Memhraniporella nitida Johns.) and Eschara con- 

 scinopora var. pliocenica Sey. living as Microporella distoma Busk, but 

 neither of these have yet been published from the Mediterranean, and 

 in fact as yet the Bryozoa have been but little studied in the extreme 

 South of Europe and North Africa. 



Professor Seguenza naturally employed the classification he found 

 used by Eeuss and Manzoni, but since the memoir was in the press a 

 new classification has been introduced which we hope will be adopted 

 in any future work from the same pen. 



In regard to the generic divisions employed we see that both the 

 genera Pustulopora and Entalophora are used. The first name was 

 given by Lamouroux and the latter by Blainville for the same 

 group, and both have since been used as synonyms, but Mauzoni 

 recently artificially separated Entalophora from Pustulopora, placing 

 in Pustulopora those with few cells, considering the only difference to 

 be that " in these the number of cells is greater than in Entalopliora " ; 

 but this is quite arbitrary, and according to this arrangement different 

 parts of the same specimen might belong to two genera. 



In the species of Terehripora and Spatipora described there 

 remains great difficulty in finding satisfactory characters by which 

 they can be separated from j3^tea, which spreads in such various ways 

 that if each was taken as having specific value the number of recent 

 species of ^tea would be largely increased. 



This valuable memoir must be constantly referred to by all 

 working at both recent and fossil Italian Bryozoa. 



Arthropoda. 

 a. Insecta. 



Germinal layers of the Insecta.* — Professor E. Hertwig is led, 

 from his observations on the Coleopteron Acilius sulcatus and the 

 Lepidopterous Noctua sp. ? and Zygcena minos, to see that the yolk- 

 cells form the enteric glandular layer, but that they are not, as has 

 been hitherto supposed, sharply distinguished from the invaginated 

 cell-mass. 



The gastrula-mouth has, from its mode of formation, the form of 

 a longitudinal cleft, and the cylindrical ectoblastic cells at its margin 

 pass into the small invaginated cells. When we compare the invagi- 

 nation of the Insecta with that of other animals we see that these 

 small cells do not form the whole of the gastrula-sac, but that there 

 are in addition to them yolk-cells; and both these elements must, 

 therefore, be regarded as forming the primary endoblast, from which 

 there is, in addition, developed the mesoblast together with the 



* Jen. Zeitschr. f. Naturwiss., xiv. (1881) Suppl. Heft, pp. 127-8. 



