450 SUMMARY OF CURRENT RESEARCHES RELATING TO 



filling up the lacunae which are now seen in zoological systems, and 

 he announces a French exploration of the Mediterranean. 



Studies on the Crustacea Decapoda.* — J. E. V. Boas has been 

 investigating the integumentary skeleton of these forms. Starting 

 with the Penfeidse, he finds that on the one side there are connected 

 with them all the other " Salicoqiies " which form a natural and allied, 

 though very distinct group, for which he proposes the name of Euky- 

 photes. On the other side we find, as descendants of the Pen^eid^, 

 the Macriu'a -|- Anomala and the Brachyura, which unite to form a 

 large and rich natural division. Of the extant forms, Homams (and 

 Nephrops) stand the nearest ; from this group, well represented in the 

 past, we have the genus Polycheles and the Loricata, and also the 

 Thalassinidae descended. Astacus is intermediate between these last 

 and Homarus ; they too appear to have given rise to the Anomala, 

 which fall under three heads — Galathfeidfe, Hippida3, and Paguridfe. 

 Porcellana is a modified Gallathid, and Litliodes a modified Pagurid. 

 The Brachyura a23i)ear to have arisen from one of the Anomala, to 

 which the Dromiace^e stand nearest. 



These views are displayed in a phylogenetic table, and in the 

 following tabular classification, which it is worth while to reproduce, 

 as by dropping altogether the division of the Decapoda into Brachyura 

 and Macrura — a division as valuable, the author thinks, as one which 

 would group Mammals as Eodents or Non-rodents — it probably marks 

 a considerable step forwards. 



SUBORDO I. NatANTIA. 



1. Penaeidae. 



2. Eukyphotfe. 



SUBORDO II. EePTANTIA. 



3. Homaridfe ( -(- Astacus). 



4. EugonidfB. 



5. Loricata. 



6. Thalassinidae. 



7. Anomala. 



a. Hippidas. 

 h. Paguroidca. 

 c. Galathaeida?. 



8. Brachyura. 



a. Dromiacete. 



b. Brachyura genuiua. 



The author has discovered that the forms known as Cerafaspis 

 longiremis and C. monstruosus are Penaeids in the Mysis-stage, but 

 they belong to forms the adults of which do not seem to be yet 

 known ; they have no relation, as Dohrn thinks, to the Schizopoda. 

 Abundant as the Penaeidae were in the Jurassic and other epochs, 

 their forms did not differ much from those now living. 



* Skrift. K. Dansk. Vidensk. Selsk., i. (1880) pp. 25-210 (7 pis.). 



