1 882.] Zodlogy. 589 



poda, judging by Leydig's figures 1 and our own observations on 

 that of Idotea and Lerolis, 2 is built on a different plan from that 

 of the Decapoda The syn-cerebrum of the Phyllocarida is 

 somewhat like that of the Cladocera and Copepoda (Calanidae) ; 

 being essentially different from that of the majority of the Mala- 

 costracous Crustacea. The Copepodous brain is an unstable, 

 variable organ, but on the whole belongs to a different category 

 from the syn-cerebrum of other Neocarida. 



We have, then, probably two types of archi-cerebra, and three 

 types of syn-cerebra among existing Crustacea. — A. S. Pack- 

 ard, Jr. 



t The Coloring of Zoo-geographical Maps.— Having had occa- 

 sion to prepare a colored map to illustrate the geographical dis- 

 tribution of the phyllopod Crustacea of North America, for Hay- 

 den's 12th Annual Report of the U.S. Geological Survey, we 

 would propose for the consideration of zoologists, the following 

 scale of colors, which we have adopted. In the colored maps al- 

 ready published, one by Mr. W. G. Binnev on the Western Mol- 

 lusks, and one by Dr. John L. LeConte to illustrate the distribu- 

 tion of the Coleoptera, the coloring does not at all agree. It is 

 highly desirable that such maps should, if possible, be uniform, 

 as much so perhaps as geological maps. 



Hon 1 (< »n li.u,')'i ; ioviiice'.'.'.'.'l!liR : . 



This combination of colors seems appropriate to the nature of 

 these regions. The pale carmine is like ice ; the blue, yellowish- 

 green and deep green characterizes the wooded portions of the 

 continent, and the light brown forms the treeless plains and pla- 

 teaus of the West. The Alpine summits of the White mountains 

 and Rocky mountains are concolorous with the Arctic regions, 

 and the summits of the Alleghanies with the Boreal province.— 

 A. S. Packard, Jr. 



Professor E. A. Birge on the First Zoea Stage of Pinno- 

 theres ostreum.— In the summer of 187S I accompanied the 

 Johns Hopkins Laboratory to Creslield. Md.. and occupied my 

 time with study on the development of decapod Crustacea. I 



foea of Pinnotheres, and so unfortun . re ir them 



beyond the first molting. I therefore send figures of the zoea in 



'Tafeln zur Vergleichenden Anatomic Von F. Leydig. Tubingen, 1864, fulio. 

 Zoology f or Hi a l, Sch »,ls an,! Collegers Fig.. 2 iS , 2 5 6. Drawn by Mr. Kings- 



