ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 453 



1. The plasticity of the eye, derived from the triune inverted eye 

 of the Nauplius, and the absence of paired compound eyes. 



2. The biramous condition of the swimming- feet, and the 

 characters of the appendages generally, especially the plasticity of 

 the maxilla. 



3. The slight development of the pleura. 



4. The absence of gills, and the functional anal respiration. 



5. The plasticity of the fore part of the alimentary canal. 



6. The circulation and heart. 



7. The general correspondence of the form of the body with that 

 of the Protozoea and Zoea larva. 



By converging arguments from these points, it is shown that 

 Copepoda would represent the most primitive Crustacea. 



New Decapod Crustacea.* — Mr. S. I. Smith describes some new 

 or little known decapod Crustacea from the east coast of the United 

 States, belonging to the genera Anamathia (1), Munidopsis (2), Bytho- 

 caris (2), Hymenodora (1), Acanthephjra (2), Ephyrina nov. gen. (1), 

 Benthoecetes (1), and Benthonedes nov. gen. (1). 



New or Rare Crustacea.f — M. Hesse, in his thirty-fifth and 

 thirty-sixth essays on Crustacea from the French coast, describes tvs^o 

 new species of Porcellana, P. navigatrix, and P. stenocheles, and takes 

 the opportunity to refer to a remarkable peculiarity of all the mem- 

 bers of the genus, namely the great development of the appendage 

 on either side of the mouth ; this is provided along its inner edge 

 vfith long setae bent at their free end, and having the function of cirri ; 

 just as in Cirripedia they seize on such passing objects as are fit for 

 food. 



A description is given of the larva of Porcellana platycheles, and 

 it is pointed out that the species, much eaten though it be by fishes, 

 has various means of preserving itself; their small size hides them 

 from their enemies, whilst their large eyes, placed on movable stalks, 

 enable them to look around in all directions ; their form is such that 

 they are able to swim with great rapidity, and their enormous rostral 

 appendage serves to cleave the water, while their large flattened abdo- 

 men acts as an excellent rudder. The seventeenth species of Anceus, 

 A. danielii, is described ; with rare exceptions, the larval Ancei are of 

 wandering habits, and before they take on the adult form they make 

 " dangerous peregrinations " to find the fish on which they are des- 

 tined to live ; the species now described however, lives at the bottom 

 of the water, and among the plants that grow there. The author is 

 unable to explain how it is that the larv^, whose mouth-organs are of 

 exactly the same form as those of the species which live on the blood 

 of fishes, do not die of inanition. 



New Crustacea from Arctic Alaska. t — Mr. J. Murdoch describes 

 seven new species of Crustacea from Point Barrow, Point Franklin, 



* Proc. U.S. Nat. Mus., vii. (1884-5) pp. 493-511. 



t Ann. Sci. Nat.— Zool., xvii. (1884) Art. No. 5, 14 pp. and 1 pi. ; Art. No. 6, 

 11 pp. and 1 pi. 



t Proc. U.S. Nat, Mus., vii. (1885) pp. 518-22, 



