524 BULLETIN 15 8, UlSriTED STATES NATIONAL MUSEUM 



Male. — Head at an angle of 45° with the trunk axis, somewhat 

 gibbous behind; trunk narrow ovate, terminating in a pair of small 

 conical caudal rami. First antennae 3-segmented; both rami of sec- 

 ond antennae 1-segmented, the exopod with a single apical spine; 

 second maxillae a little longer than maxillipeds, the apical claw 

 shutting into a socket on the inner margin of the basal segment. 

 Total length, 1.45 mm. 



Remarks. — The protruding maxillary glands on the sides of the 

 neck and the relative length of the two pairs of posterior processes 

 are the chief characteristics of this species. 



Family SPHYRIIDAE 

 Genus PAEON Wilson, 1919 



Female. — Body separable into head, neck, and trunk. Head en- 

 larged into a transverse ellipsoid, the surface of which is raised into 

 globular paired processes ; neck slender and straight but usually show- 

 ing torsion; trunk swollen and depressed, with a pair of posterior 

 processes dorsal to the ovisacs. Abdomen minute, fused with the 

 trunk and carrying a pair of globular caudal rami. No antennae; 

 proboscis retractile; two pairs of mouth parts; no swimming legs. 



Male. — Head elongate, covered with a carapace and gibbous pos- 

 teriorly; one free thoracic segment, the others fused into a trunk 

 with a pair of conical caudal rami and a pair of minute clactylose 

 processes in front of them on the ventral surface. First antennae 

 indistinctly segmented; second antennae biramose; four pairs of 

 mouth parts, the basal segments of the maxillipeds completely fused, 

 the terminal segments usually chelate. A single species here. 



PAEON ELONGATUS, new species 



Plates 40, 41 



OcGwrrence. — Both sexes were taken from the gill cavity of the 

 brown shark {G archarJiinus tnilberti) and also from the gill cavity 

 of the dusky shark {C. ohscurus), both captured at Menemsha Bight, 

 Marthas Vineyard. A single female with attached male has been 

 selected for the holotype of the new species, with U.S.N.M. No. 56655. 



Color. — Body a uniform milky white, the globular processes on 

 the head usually tinged more or less deeply with reddish brown. 



Female. — Head enlarged transversely into an ellipsoid, from the 

 anterior and ventral surfaces of which project several pairs of 

 globular processes. The first pair extend across the anterior margin 

 and are nearly spherical, but their surfaces meet on the midline and 

 are somewhat flattened. Behind them on the ventral surface is a 

 transverse series of three knobs, the end ones subspherical, the middle 



