DICHELASPIS PELLUCIDA. 125 



with a row of beads on the crest. Palpi small, with few 

 bristles. Mandibles, with the whole inferior part, very 

 narrow ; three teeth very sharp, with a slight projection, 

 perhaps, marking the place of a fourth tooth ; inferior 

 angle ending in the minutest point ; first tooth as far 

 from the second, as the latter from the inferior angle. 

 MaxillcB with a broad shallow notch ; inferior angle much 

 rounded, bearing only four or five pair of spines. 



Cirri. — First pair apparently remote from the second 

 pair ; all five posterior pair lost ; first pair short, with 

 the rami unequal by about two segments ; segments 

 clothed with several transverse rows of bristles « terminal 

 segments blunt. 



3. DlCHELASPIS PELLUCIDA. PL II, fig. 7. 



D. valvarum singidarum acuminibus superioribus ei 



inferioribus vice intersecantibus : senior urn segmento basali 



multo angnstiore quam segmentum occludens ; lo7igitudine 



fere dimidid : tergis bipenniformibus, margine integro, 



manubrii acumine ad carinamjlexo. 



Valves with the upper and lower points of the several 

 valves only just crossing each other. Scuta with the basal 

 segment much narrower than the occludent segment, and 

 about half as long as it. Terga like a battle-axe, with 

 the edge smooth, and the point of the handle bent to- 

 wards the carina. 



Mandibles with four teeth ; caudal appendages twice 

 as long as the pedicels of the sixth cirrus. 



Indian Ocean ; attached to a sea-snake. 



This species comes very close to the D. Gragii, which 

 likewise was attached to a snake ; but I cannot persuade 

 myself, without seeing a graduated series, that the differ- 

 ences immediately to be pointed out can be due to 

 ordinary variation. I am much indebted for specimens 

 to the kindness of Mr. Busk. 



