874 RECOBD OF CURRENT RESEARCHES RELATING TO 



The total number of species recorded is 73, of which 45 are 

 Decaj)ods, 11 Schizopods, and 17 Cumaceje, one-half of which are also 

 to be found in Europe, the author concluding that there is not only a 

 close relationship between the marine fauna of Greenland and that of 

 Northern Europe, but a similar close one between that of Greenland 

 and of the coasts of the continent of North America. 



Some New Cymotlioida.* — Herr Koelbel describes some new 

 species of this group from various localities in a paper which is illus- 

 trated by two plates ; among these is a representative of a new genus 

 Emphylia, which is allied to Nerocila of Leach, but is distinguished 

 from it by the approximation of the bases of its internal antennae. 

 The single species receives the name of ctenophora, and the habitat is 

 stated to be Akyab. There are no points in the paj)er of general 

 interest. 



Trilobites and Limiili.t — Professor E. von Martens recapitulates 

 the history of the Trilobites, which, so characteristic of Silurian 

 deposits, are never found in any strata later than those of the Permian 

 epoch. He points out that their relationship to the Isopoda is opposed 

 by the freedom of the head in these latter, and by their constant pos- 

 session of seven thoracic and seven abdominal segments, vvliile in the 

 Trilobites the cejihalic and thoracic portions are always fused and the 

 number of segments is inconstant. With regard to the view of Pro- 

 fessor Glaus that the Trilobites are allied to the Phyllopoda, it is 

 allowed that in these extant Crustacea numerous points of similarity 

 are to be observed. 



Turning to the Limuli (American king-crabs) the author points 

 out that they are to be distinguished from all other forms of 

 Crustacea by the fact that there is only one pair of prae-oral appen- 

 dages ; in this point they agree with the Arachnida, and with this 

 class some modern zoologists would place them ; when, however, we 

 consider the points by which the Crustacea and Arachnida are dis- 

 tinguished, and then study the characters of Limulus, we may see that 

 the view of Professor von Martens is, at any rate, highly probable. 

 The Arachnida are remarkable for the absence of abdominal appen- 

 dages, the presence of simple eyes only, the straight intestine, and the 

 possession of Malpighian vessels. None of these characters are pre- 

 sented by Limulus ; it, like all Crustacea, has abdominal appendages, 

 branchial organs, genital orifices situate at the boundary between the 

 thorax and abdomen, compound eyes and a true proventriculus. Ob- 

 servation of living forms has recalled to Professor von Martens the 

 great similarity between Limulus and the Phyllopod form Apiis cancri- 

 formis, and he concludes with stating that in his opinion we have both 

 in the case of Limulus and of the Trilobites, to do with special and 

 isolated orders of the Crustacea, both of which have taken their origin 

 from the Phyllopoda. 



* ' SB. Akad. Wiss. Wien,' Ixxviii. (1879) p. 401 

 t ' Naturforscher,' xii. (1879) p 377. 



