206 CEYLON PEARL OYSTER REPORT. 



free joint a little narrower than the head, second joint and genital segment con- 

 siderably wider. The latter sends out a blunt rounded process on either side of, and 

 nearly as large as, the abdomen. No appendages are visible on these processes or 

 elsewhere on the genital segment. Abdomen very small and nearly sjjherical, with 

 a pair of minute anal papillae, each of which ends in three small setse. First antennas 

 slender and apparently six-jointed ; second pair large and terminated by a stout 

 prehensile claw. Mouth-tube short and narrow and bluntly rounded at the tip ; 

 second maxillae and first maxillipeds in the form of two small papilla? on each side of 

 the mouth-tube, each tipped with a single seta. Second maxillipeds slender, the 

 terminal joint shorter than the basal. Two pairs of biramose legs placed close behind 

 the second maxillipeds ; basal joints rounded and flattened lamina?, rami linear and 

 cylindrical; exopods two-jointed, endopods one-jointed. Spermatophores comparatively 

 very large and attached by long delivery ducts. 



Colour a pale yellow, the ovaries and internal oviducts showing a dark brown 

 through the transparent integument. 



Total length 1'07 millims. ; length of free thorax 0'35 millim. ; length of genital 

 segment 0'5 millim., width of same 0*48 millim. 



Family: LEEN^EIDiE. 

 Peniculus, Nordmann. 



Head oval or elliptical, elongate, without horn-like processes, connected with the 

 body by a short and narrow neck, which is made up of two distinct thorax segments. 

 Body a fusion of several thorax segments, elongate, wider than the head, and 

 sometimes prolonged posteriorly into two elongate flattened processes. 



Abdomen small, consisting of a single joint and carrying minute anal papilla?, which 

 are tipped with non-plumose setae. Egg-strings filiform ; eggs large and uniseriate. 



First antenna? reduced to mere knobs ; second pair large and chelate, projecting in 

 front of the head and forming the chief organs of prehension. Mouth a simple tube 

 projecting from the ventral surface of the head ; mouth-parts entirely wanting, except 

 a single pair of very rudimentary maxillipeds beside the mouth tube. Four pairs of 

 rudimentary swimming legs ; first two pairs placed close behind the head, third and 

 fourth pairs some distance from them and from each other. 



Male smaller than the female and with a shorter thorax ; posterior processes also 

 shorter than those of the female, but wider and truncate at the tip. 



Peniculus furcatus, Kroyer Plate V., figs. 61 to 66. 



Female. Head elliptical, slightly widened posteriorly, about twice as long as wide, 

 with evenly curved sides. Posteriorly the head passes into a neck of about half its 

 width, made up of three thorax segments which are distinctly separated on both the 

 ventral and dorsal surfaces. The fourth and genital segments are fused, with no line 



