208 ANIMALS OF THE SEASHORE 



MYSIDACEA 



These are small, elongate Crustacea usually less 

 than an inch in length. The appendages of the 

 thorax (head region) are branched (biramous) — 

 hence the name Schizopoda (meaning cleft-footed) 

 by which these animals were formerly called. No 

 gills present. 



Numerous species are known from our coast, 

 although only one is common in New Jersey. 



Mysis americana Smith (Opossum Shrimp) 



About half an inch in length, translucent with 

 prominent eyes. Particularly common in winter 

 and early spring on the surface of shallow water, 

 especially in Delaware Bay. These small animals 

 form an important part of the food supply of many 

 of our food fishes. 



In this species the eggs are carried in pouches 

 under the thorax, giving the common name "Opos- 

 sum shrimp." 



EUPHAUSIACEA 



These shrimp-like crustaceans were formerly 

 grouped with the Mysidacea in the Order Schizopoda 

 because in common with them the thoracic append- 

 ages are biramous. However, they differ from the 

 Mysidacea in having gills attached to the thoracic 

 legs. They are considered as of much higher degree 

 of development and are classified nearer the decapod 

 crustaceans. 



