120 bulletin: museum of comparative zoology. 



in the small specimens less triangular and rounded laterally. In the anterior 

 segments rudiments of pleopods are either scarcely discernible or visible as very 

 low and broad rounded eminences. 



Size. The largest specimen (Fig. 2/) is 4.8 mm. long ; a smaller specimen 

 from which the three analytical figures have been drawn, is 3.5 mm. long ; 

 a small specimen is only 2.9 mm. long. 



Habitat. The label indicates that the five adult females (with their males) 

 were found in the branchial cavity of Galacantha diomedece var. parvispina 

 Fax., from Station 3435 (Lat. 26° 48' 0" N., Long. 110° 45' 20" W.), 859 

 fathoms. In the Eeport on the Stalk-eyed Crustacea of the " Albatross " Ex- 

 pedition of 1891, W. Faxon writes (p. 81) : "Seven specimens (5 males, 2 

 females) of var. parvispina house a Bopyrus in the left branchial chamber." 



13. Parargeia ornata, n. gen., n. sp. 



Plate VI. Fig. 1 - 1 1. 



Only one female and its male are found. 



a. Female. 



The body is much distorted and scarcely 1^ times longer than broad. 



Head. It is comparatively very broad, but otherwise of the same shape as 

 in Munidion {ante, p; 115). The antennulae (Fig. lb) separated by a frontal 

 plate (p), of medium size, 3-jointed; the basal joint comparativ^ely long 

 and thick, the second short and narrow, the third exceedingly small. The 

 antennae (b) similar in shape to those of Pseudione (see above), but larger 

 and 6-jointed ; the basal joint very large, forming about an oblong oval, with 

 both margins a little convex ; the second joint is attached at the antero-exterior 

 angle of the first, and is tolerably short and slender, yet longer and considerably 

 thicker than the third; the three distal joints are exceedingly small. The 

 frontal plate (p) rather large, about three times broader than long, anteriorly 

 emarginate. The labrum exceedingly large, in the middle very short, but on 

 each side forming a large oblique plate (c) which overlaps the distal part of 

 the mandible and the maxillula, and the lateral part of the hypopharynx. 

 This organ (h) is triangular and broader towards its base than in the preceding 

 forms. The mandibles (d) extend in the middle with their acute tip beyond 

 the end of the hypopharynx. Maxillulse (e) and maxillae (/) need no men- 

 tion. The left maxilliped is shown in Figure 1 c ; the palp consists of a 

 prominent basal part and a small terminal joint. The border behind the 

 maxillipeds well developed, with two pairs of long, oblique, distally slender 

 processes. 



Thorax. Ovarian bosses are found on the four anterior segments ; they are 

 oblong, considerably convex, and occupy from less to more than half of the 

 sub-lateral portion of each segment. By a conspicuous or even deep furrow 

 they are set off from the anterior part of the pleural plates, which lie outside or 

 more beneath the bosses, are much arched, and look almost like " epimera " in 



