608 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxviii. 



view of the marked similarity between this single specimen and the 

 female productus, it will at least be necessary to wait for further speci- 

 mens whose sex can be established beyond a doubt before admitting it 

 as a new species. 



This completes the North American species so far as known at the 

 present time, but there are in the National Museum collection, speci- 

 mens of another species from South America which seem to be new to 

 science and whose description is here included. (See p. 649.) 



Genus CALIGODES Heller. 



Carapace minute, a very small fraction of the entire length. Fron- 

 tal plates well defined and furnished with lunules. First maxilla? 

 small with a swollen base; second maxillse simple. Furca large and 

 prominent with the divergent and sharp-pointed branches bent so as 

 to appear like a grapnel anchor in side view. Free segment narrow 

 and somewhat elongated, forming a neck connecting the carapace with 

 the genital segment. 



First and fourth legs uniramous, second and third biramous, the 

 fourth pair sometimes partially rudimentary. 



Genital segment much swollen and prolonged posteriorly into two 

 processes as long as the abdomen and extending backward nearly 

 parallel with it on either side. Fifth legs lacking. 



Abdomen elongate and flattened; anal laminse linear and minute. 



Egg cases long and narrow; eggs as in Caligus. 



{Caligodes, Caligus, and odes, a termination denoting likeness or 

 similarity.) 



This genus will be distinguished from Eclietus under the latter 

 genus (see p. 615), and it only remains to separate it here from van 

 Beneden's genus, ScisenopMlus. In the latter the free thorax seg- 

 ment is very short and wider than long, as it is in Caligus, while in 

 the present genus the free segment is much elongated. Again in 

 Scid&nophilus the genital segment is without processes or appendages, 

 while here it is prolonged on either side into an appendage as long and 

 as large as the abdomen. In Scisenophilus, also, the second maxillipeds 

 are very large and massive, while here they are of moderate size. 



ANALYSIS OF SPECIES. 



1. Abdomen wide and produced into posterior lobes; fourth legs four-jointed with 



five spines carangis (B-Smith, 1898, b). 



1. Abdomen without lobes or processes, of medium width 2. 



2. Processes on genital segment longer than the abdomen; fourth legs inserted 

 close to the carapace, two-jointed with two spines. 



megaceplialus, new species. 

 2. Processes on genital segment shorter than the abdomen; fourth legs inserted 

 some distance back of the carapace, three-jointed with one small spine. 



laciniatus (Kroyer, 1863). 



