1 INTRODUCTION. 



The genera of the sub-family LYSTANASSINA appear to 

 be very generally diffused over the entire globe, increasing 

 in dimensions in those species that approach nearer to the 

 Arctic and Antarctic latitudes, in some instances reaching 

 to the largest known of the order, equalling three inches 

 in length, as may be seen in Lysianassa Magellanica, from 

 the Straits of Magellan, and L. gryllus, from Spitzbergen. 

 These two so closely resemble one another, that they can- 

 not be characteristically distinguished. 



The genus Ampelisca, and its near ally Haploops, we 

 only know as belonging to the Northern Hemisphere, but 

 in that region extending from Japan to Europe, from 

 Greenland to North Carolina on the coast of America, 

 and in Europe to the Mediterranean Sea. 



In the sub-family PHOXINA all the genera but one are 

 only known in the north temperate region, but with a 

 widely diffused area, extending from Japan to Europe. 

 One species of the genus (Ediceros has been taken in New 

 Zealand, and one of Iphimedia in Terra del Fuego. Of 

 the former we have our doubts in its relation to the 

 genus ; the latter has a very near resemblance to /. Eblance 

 of Europe. Most of the genera of this sub-family are 

 burrowers in mud or sand. Isaea dwells, without being 

 parasitic, on the back of hairy crabs, and the only 

 specimens of Darwinia, that have been taken alive,' were 

 found adhering to the throat of a cod-fish. The genus 

 Sulcator lives on sandy shores, making tracts along the 

 margin of the sea, somewhat similar to those found in 

 older slate and sandy rocks; and it may be interesting 

 to remember that we have attributed to this sub-family 

 the only Amphipod that has been hitherto discovered as 

 fossil, the Prosoponiscus problematicus of the magnesian 

 limestone of Durham, and Zechstein- dolomite of Gliicks- 

 brun. 



