ISOPODS OF NORTH AMERICA. 



479 



ing ones small, the last fring'ed with hairs. The socoiul pair of siiiten- 

 mv have a rudimentary flagelluni, consisting of live or six joints; the 

 peduncle has the third and fifth joints long and oval in shape, the 

 fourth joint somewhat triangular. 



The thoracic segments are looselv articulated. The lateral mar- 

 oins are straight, with no indication of 

 epimera. 



The terminal segment of the body is 

 rounded in outline, the posterior margin 

 excavated at the insertion of the uropoda, 

 which do not extend beyond the edge of 

 the segment, thus preserving the oval 

 outline. Between the uropoda there is 

 an acute median projection. 



The legs are all simple, with bi-unguic- 

 ulate dactj'li. 



One specimen was collected by Prof. 

 A. E. Verrill and party at the Bermudas, 

 and another l)v Dr. G. B. (xoode, from 

 the same locality. 



Type specimens in Peabod}^ Museum, 

 Yale University. Cat. No. 3251. 



Six species of this genus have been 

 heretofore described: Jsei'opsis lobata 

 Kci'hler, Jmropsis vuirionis Beddard, 

 Jirropslx neo- Zealand ica Chilton, J^vrojjsis 



lobata Richardson, ^Iperopsis dollfusi Gorman, and Jaeropsis curvicornis 

 (Nicolet).-' The present species adds another to the above list. 



It is named in honor of Miss Mary J. Rathbun. 



Fig. 537.— J.EROPSIS RATHBtN.K. (1, 



Head and first thoracic segment. 

 &,-Maxilliped. c, Terminal seg- 

 ment AND UROPODA. d, MaNDIBLE. 



e, Mandible (another vtewI. 



Family XVIII. MUNNID.*].'' 



Body ovate, short and stout, with the three posterior segments of 

 the thorax sharply marked off from the four anterior ones and much 

 smaller, and gradually becoming narrower. Terminal segment of 

 body vaulted above, subpyriform. 



Eyes, when present, placed on the tips of lateral peduncle-like pro- 

 jections of the head. First pair of antenna^ placed widely apart, with, 

 the tiagelluni nudti-ai"ticulate. Second pair of antenna^ without scale. 



First pair of legs much shorter than the following pairs and pre- 

 hensile. Succeeding pairs more or less rapidly increasing in length, 

 simple, aml^ulator}'. Uropoda small, somewhat separated. 



Pleopoda as in the Janiridae. 



(^Jiera curvicornis Nicolet, in Gay's Hist, de Chile, III, 1849, p. 263, Zool. Atlas, 

 Crust., No. .3, fig. 10. This species should be referred to the genus J.Tropsis. 

 ''See Sars for characters of family, Crust, of Norway, II, 1899, p. 105. 



