384 A HISTOEY OF RECENT CRUSTACEA 



flattened and ciliated. The incubatory pouch in the female 

 is generally under the first four segments of the perason. 



The swimming joints above described resemble those 

 found on some of the swimming crabs, and differ strikingly 

 from what is customary among the Isopoda. To this 

 family, indeed, the title of equal-legged animals is singu- 

 larly inappropriate. 



Munnopsis, Michael Snrs, 1861, has the body suddenly 

 constricted and slender behind the fourth peragon-segment. 

 The second antennae are very elongate, with the peduncle 

 six-jointed. The mandibles are acuminate, with a second- 

 ary plate on the left, but not on the right mandible, with- 

 out molar, and with a three-jointed 'palp.' The first and 

 second limbs of the perseon are short, rather robust, sub- 

 prehensile, the two following pairs enormously elongated ; 

 the three following pairs are natatory, without a seventh 

 joint. The arrangement of the pleopods corresponds with 

 that already described in Janira. The uropods are slender,, 

 single-branched. Munnopsis typica, Michael Sars, the type- 

 species, has a very extended boreal distribution in deep 

 water on muddy ground. Hansen says that in the second 

 antennas the long fourth and fifth joints of the peduncle 

 are immovably fused. In these organs the flagellum is 

 nearly as long as the peduncle, and the two together are 

 about five times the length of the body. By the great 

 elongation of the fifth and sixth joints in the third and 

 fourth limbs these equal about three times the body's 

 length. Munnopsis australis, Beddard, with no ' palp ' to 

 the mandibles, and with the marsupium arising apparently 

 only from one segment of the perreon, must probably be 

 referred to a separate genus. 



Eurycope, Sars. 1864, has the body not abruptly con- 

 stricted. The second antennas are very elongate, with six- 

 jointed peduncle. The mandibles have a spine-row, molar, 

 and three-jointed ' palp,' but no secondary plate on either 

 mandible. The first pair of limbs are rather short, the 

 next three pairs are long, and the last three pairs are nata- 

 tory, with an unguiform seventh joint. The pleopods 

 are as in the preceding genus. The uropods are short, 



