ISOPODS OF NORTH AMERICA. 



561 



TicoLA. First incubatory 



LAMELLA. X 51|. 



parts large and expanded. On th(> shorter side they are less expanded 

 and upeiirv ed, showing the legs. Ovarian bosses are not present on 

 any of the segments. The lateral margins of all the segments of the 

 expanded side ai-e entire with the exception of the secontl, which has 

 a decided notch separating the anterior two- 

 thirds from the posterior third. The epimera 

 seem to be perfectly coalesced in all the seg- 

 ments with the dorsal pai't of the segments. 

 The segments of the a))d()men are all fused 

 in the middle of the dorsal surface. On the 

 shorter side of the body there is no indication 

 of the segments, the lateral margin being- 

 straight and continuous. On the opposite fig. 615.— probopyrus latreu 

 side, however, tive distinct segments are 

 marked oti' from the terminal lobe by five 

 de(>p notches. There are tive pairs of double-))ranched i)leopoda in 

 the form of small, rounded lamella?. No uropoda are developed. 

 The tive pairs of incubatory lamelUv do not completeh' inclose the 

 marsupial pouch. The plates are small and bound only the lateral 

 parts of the marsupium. The distal segment of the tii-st pair is pos- 

 teriorly rounded. Tiierc^ are seven pairs of legs, all e((ually well 



developed and having pre- 

 hensile hands. 



The male is ()l)long-ovate. 

 The anterior margin of the 

 head is widely rounded. 

 Eyes are distinct. The 

 seven segments of the 

 thorax are distinct and 

 have the lateral margins 

 rounded. The segments of 

 the abdomen are fused in 

 the middle, l)ut are all dis- 

 tinctly markt'd at the sides. 

 Five deep notches separate 

 the tirst Hve segments from 

 each other and from the 

 sixth or terminal segment, which has the posterior margin produced 

 in three small lobes, one median and one on either side, all in a trans- 

 verse line. There are no uropoda nor pleopoda. The abdomen is not 

 abruptly narrower than the thorax. 



The specimen described is found parasitic on Latreutes tnsifents 

 (Milne Edwards). 

 28589—05 36 



f> 



Fig. 016.— Probopyrus latreuticola. «, First pleopod 

 (showing both branches). X 54|. b. Second pleopod. 

 X 103^. c. Third pleopod. x 1031. rf, Fourth pleo- 

 pod. X 103J. 



