TWO NEW ISOPODS — PEARSE AND WALKER 21 



panded distally; and the fourth (iv) are notched and extend to the 

 abdominal pleura. The brood chamber is closed in most adults. All 

 oostegites are supported by chitinous thickenings arranged like the 

 veins in an apple leaf. The last three abdominal appendages are 

 absent, but pleural folds are present along the lateral margins, those 

 of the first three form complicated folded structures. 



Male. — Body (fig. 12, A., C) slender, tapered toward posterior end; 

 length 2.1 mm. Head weakly trilobed in front, twice as wide as 

 long, anterior less than half width of posterior margin, two small, 

 laterally elongated eye spots near posterior angles. Antennae ab- 

 sent ; antennules 1-segmented, very short, not reaching beyond frontal 

 margin, with 11 setae at tip. The styliform mandibles are enclosed 

 in a suctorial oral cone. Thoracic legs (fig. 12, C\ E) stout, 5-seg- 

 mented; the penultimate segment expanded distally; the terminal 

 segment much narrower, conical, and bearing two spines at its tip. 

 Abdomen without appendages; terminal segment notched at tip and 

 the rami acute. Males were always found attached to females. 



Development. — During July eggs and developmental stages were 

 found (fig. 12, /<', G) in females, and on September 2 a female with 

 epicarid larvae in her brood pouch was found (fig. 12, H., I). The 

 latter were remarkable for the great length of their last thoracic 

 legs {t-7) and swam about actively in sea water. In July wormlike 

 young females of various sizes were found. Apparently the epicarid 

 larva molts into a young female without appendages (fig. 12, /). 



Occurrence. — Females occurred in various positions in the thoracic 

 cavity of crabs, and males present were clinging to them. Once two 

 mature females were present in one crab; in another crab there were 

 a mature female and two young females. In the 622 crabs examined 

 at Beaufort 3 males, 5 mature females, and 5 young females were 

 collected. The best collecting ground was found to be the marsh 

 east of the railroad bridge at Beaufort; 51 crabs examined from 

 other localities yielded nothing. 



Types. — Female holotype, U.S.N.M. No. 77217, from Panopeus 

 hei'bstii Milne Edwards, Beaufort, N. C, September 2, 1938. Male 

 allotype, U.S.N.M. No. 77218, same locality and host, July 13, 1938, 

 A. S. Pearse, collector. 



CANCRION NEEDLERI, new species 



Figure 13 



Only one pair of this entoniscid was collected in the body of the 

 first crab examined at Ellerslie, Prince Edward Island; 226 other 

 crabs were searched carefully but no more parasites were found, ex- 

 cept one other dead, shriveled female entoniscid. 



Female. — Body straight; abdomen not flexed on thorax; length 

 18 mm. The rounded frontal lobes project dorsally and anteriorly; 



