with descriptions of two new species. 23 



of a small pea, of an oval form and very convex, rounded at the 

 base and somewhat pointed at its apex, under which anteriorly it 

 is deeply notched. The shell is smooth, shining, and of a pale 

 yellow or cream colour (dry). 



Two or three specimens were brought home by Mr. Arthur 

 Adams, Assistant Surgeon Royal Navy, attached to H.M. Ship 

 ' Samarang,' who dredged them during the late voyage of that 

 vessel in the South Atlantic Ocean. They had as well as the 

 preceding species been preserved dry, and from the long time 

 they had been kept so, it was almost impossible to dissect the 

 animal. However by steeping them in spirits of wine for some 

 time, I succeeded in obtaining the body of the animal sufficiently 

 entire to be able to ascertain the genus. The anterior antenna 

 (fig. 2) consists, as in the preceding species, of four joints, the 

 three last having numerous pretty long plumose setse springing 

 from the upper edge, and the last being terminated by a tuft of 

 similar but longer setse. The natatory foot (fig. 3), as in the 

 other species, consists also of a very large basilar joint which 

 gives origin to two branches; the upper of which consists of one 

 very long joint and six very short ones, from the base of each of 

 which issues a long plumose seta. The oviferous foot (PI. VII. 

 fig. 4) resembles very much that of the preceding species, being 

 cylindrical, and beset at its upper extremity with spines. The 

 jaws and tail resembled very much the same organs in C. Mac- 

 Andrei, but the body of the animal was too much decomposed 

 to allow me to see them sufficiently accurately to be able to figure 

 them. 



Godeheu de Riville, in his paper on the Luminosity of the Sea, 

 published in 1760 in the third vol. of the 'Memoires pour les 

 Savans Etrangers,' describes a small Entomostracan which must 

 belong to this genus. Sailing along the coast of Malabar, when 

 in 8° 47' N. lat., and in 73° E. longitude of Paris, the sea was 

 obsei'ved to be unusually and most brilliantly luminous. Having 

 had his attention previously directed to this interesting phseno- 

 mcnon, Riville determined to ascertain the cause. The water all 

 round the vessd and to a considerable distance from it was white 

 as snow, and in the wake of the ship innumerable star-like bodies 

 of a still brighter lustre sparkled on the surface of the agitated 

 surf. He had some water drawn up from alongside, and he then 

 observed numerous bright sparkling spots in the bucket in which 

 it was contained. Poui'ing it out upon apiece of linen, numbers 

 of small bodies still giving out light were observed adhering to 

 the surface of the cloth. They were alive, and resembled, he says, 

 " those small insects called in France Puces d'eau." The body 

 of the animal was contained in a little shell which was transpa- 

 rent, and resembled in form an almond cleft on one side and 



