344 PROCEEDINGS OF THE NATIONAL MUSEUM VOL. loi 



exterior of the endopod setose, that on the median edge of the 

 exopod smooth ; second segment of exopod with two spines and a 

 plumose seta ; terminal segment with two spines and seven plumose 

 setae ; first segment of endopod with a median plumose seta ; second 

 segment setose laterally and with two plumose setae medially ; third 

 segment with six plumose setae. Third leg biramous; with a 

 laminate segment that bears a strong hook ; exopod 2-segmented ; 

 the terminal segment ending in a spinose disc ; the endopod 1-seg- 

 mented and also ending in a spinose disc. Fourth leg 3-segmented ; 

 first segment short ; second segment almost 20 times as long ; third 

 segment one-fourth longer than second, tipped with four long 

 setae. Fifth legs on genital segment are laminate plates with four 

 plumose setae. 



Measurements : Body 1.55 by 1.52 mm. ; genital segment 0.2 by 

 0.5 mm. 



Female. — Unknown. 



Type.— V.S.N. M. No. 88576. 



Host.— The sheepshead, Archosargiis probatocephalus (Wal- 

 baum) ; on gills. 



Remarks. — The name indicates that the species is short. Wilson 

 (1905) described no males. This may be the male of Aneuretes 

 heckelii Kr0yer (1863) or A. parvulus Wilson (1913) , but there is 

 no furcula, and the mouth parts and legs are so different that it 

 seems desirable to make a new species for it ; e.g., the second anten- 

 na has a seta and a spine on the inside of the terminal hook, the first 

 maxilla has a lateral spine; the legs are different in proportions 

 and armature, and the caudal rami are wider and more triangular 

 than in Kr0yer's species ; the third legs terminate quite differently 

 from Wilson's species. 



Genus CALIGUS Muller 



CALIGUS ASPERIMANUS, new species 



Figure 68 



Female. — Carapace somewhat shorter than remainder of body, 

 slightly wider than long, the sides spreading a little posteriorly ; 

 posterior sinuses rather deep and wide; median lobe rounded. 

 Free thoracic segments short and narrow. Genital segment barrel- 

 shaped ; about as long as abdomen. First segment of abdomen two- 

 thirds as long as second; anal sinus well marked. Caudal rami 

 less than half as long as second segment of abdomen ; terminated 

 by three plumose setae and three short spines, ciliated near tips 

 medially. 



