258 CEYLON PEARL OYSTER REPORT. 



Telson entire, oblong-oval, concave above, reaching to the end of the peduncle of 

 the 3rd uropods (fig. 16. ur.). 

 Length 4 niillims. 



Leucothoe, Leach, 1813. 

 Leucothoe spinicarpa (Abildgaard). 



Generally distributed. 



I can find no differences in the specimens examined to justify referring them to 

 any later species. In a male, 7 millims. long, from Cheval Paar the distal half of the 

 palm of the second gnathopod was more deeply toothed than in Saks' figure, while in 

 smaller specimens from the same tube it agreed. The hind angle of the 3rd pleon 

 segment varies from a blunt right angle to an acute angle in different specimens. 



Leucothoe hornelli,* n. sp. Plate III., figs. 17. 



Various localities : in the branchial sacs of Tunicates, &c. 



Head as long as the 1st body segment ; ocular lobe square, with the upper and 

 lower angles rounded. 



Eyes large, dark, pyriform, with the small end lowest. 



Segments of the mesosome subequal ; first 4 side-plates scarcely deeper than the 

 segments. 



First and 3rd jjleon segments respectively longer than the 2nd ; posterior angle of 

 the 2nd acute ; the 3rd has the hind margin of the epimere at first straight, then 

 abruptly incurved, forming a sinus above the acute and slightly upturned angle 

 (fig. 17. pi. 3 ). 



Antenna?, mouth organs, maxillipeds, and 1st gnathopods as in L. spinicarpa. 



Second gnathopods : hand more than twice as long as wide ; front margin almost 

 straight or very slightly convex ; hind margin with a deep sinus about one-third of 

 its length from the base of the dactylus, followed by 2 smaller sinus, the 3rd being 

 close to the base of the dactylus. In other respects the limb resembles L. spinicarpa 

 (fig. 17. gn. 2 ). Perseopods as in L. spinicarpa. 



Third uropods with the inner ramus almost as long as the j^eduncle, outer about 

 one-fourth shorter (fig. 17. up. 3 ). 



Telson reaching beyond the end of the peduncle of the 3rd uropods, tapering 

 gradually to a very diaphanous blunt point, with 2 small spines on it (fig. 17. up. 3 ). 



Length, 5 millims. to 6 millims. 



This species resembles L. spinicarpa very closely, except in the sculpture of the 

 hand of the 2nd gnathopods and the posterior angle of the 3rd pleon segment, which 

 is nearer L. lilljeborgii, Boecic. In young specimens, 2 millims. long, " from Rltabdo- 

 oynihia, Station XIX.," the characteristic indentation of the 2nd gnathopod is plainly 



* Named after Mr. Jas. HOENELL, F.L.S., now Marine Biologist to the Ceylon Government, by whom, 

 when assisting Professor Hekpman, many of the species of Amphipoda described in this work were taken. 



