HIGTIHR CRUSTAC1':A OI- XI'.W YORK CITY 169 



Aeginella longicornis Kr. 



A c g i n c 1 1 a 1 o n g' i c o r 11 i s Kroycr. 



Anteniuilae eloiig'ate, more than twice as l()nJ4' as antennae. 

 ]\ran(lil)les with a palp. Second gnathopoda with two large teeth 

 on the palm. ])0(ly either smooth or thickly covered with short 

 slender spines. 



Fi?- 39 Aeginella- longicornis - | 



W 



Length 10-25 mm. Color variable. f 



Large specimens taken among hydroids in Great South bay. j) 



Smaller ones were taken all along the bays among hydroids and | 



algae. ft| 



Suborder b ISOPODA |l 



xArthrostraca with body flattened dorso-ventrally instead of later- i 

 ally. The gills are borne on the abdominal appendag'es. 



The antennulae and antennae are much as in the Amphipoda, 

 the former with a peduncle of three, and the latter of five segments, 



and a flagellum. Eyes composed of groups of ocelli and nearly | 



' . . . . ' I 



always sessile. The first thoracic appendage is a maxilliped, and I 



the next seven (occasionally only six) are walking legs and usually | 



all alike, wdience the name Isopoda, or ecjual-footed. A part of the I 



basal joint, or coxa, of the leg is fused wdth the dorsal part of the | 



body and is known as the epimeron. A suture, known as the Ij 

 epimeral suture, usually shows the line of fusion. The abdominal 



segments are smaller than the thoracic and are frequently more or J 



less united. The first five bear delicate lamellar appendages wdiich | 



function as breathing organs and the last pair are modified into | 

 uropoda. 



Though not a large group, the members of the Isopoda are prob- 

 ably more wddely distributed than anv other of the Crustacea. 



