IMPEEFECTLT-KNOWN OSTEACODA. 181 



(fig. 23) ; anterior extremity wide, irregular, truncated, but with a very deep median 

 sinus, posterior sharply truncated, but concave and fringed with hairs ; lateral 

 margins very irregular, with many sinuations, elevated at the anterior third whence 

 they slope irregularly towards either extremity ; surface of the shell marked through- 

 out with extremely irregular crested ridges and bosses. Length 4 4 mm. Joints 

 of the antennae not produced into lateral spines, secondary brancli with a narrow, 

 elongated hand (fig. 24j which is slightly dilated distally and bears a brush of numerous 

 hairs ; terminal claw strongly falcate, bulbous at the base, and slightly so at the apex, 

 a single stout seta at the base; penultimate joint of the mandibular foot bearing a 

 digitiforra appendage. Postabdominal laminae armed with live long and slender 

 pectinate claws. 



Hah. Lat. 0" 37' N., long. 109° 47' E. One specimen only. 



Genus Cyclasteeope G. S. Brady i. 



This genus was founded on a species taken in Madras Harbour, the name being 

 suggested by the circular outline of the shell, supplemented by certain anatomical 

 characters. The shape of the shell can no longer be maintained as a generic character, 

 several other species having been discovered, which with a very different form of shell 

 combine the other distinctive characters of Cyclasterope. The points which I now 

 suggest as diagnostic of the genus are the presence of a digitiform process on the 

 penultimate joint of the mandibular foot, the profusely setiferous character of the 

 vermiform limb, each ring of which toward the distal extremity usually supports two or 

 three setae, and the spinous armature of the joints of the swimming-branch of the 

 antenna. 



Cyclastekope fascigeka, sp. nov. (Plate XXI. figs. 20-31.) 



Male. Shell seen from the side subovate, slightly higher behind than in front, 

 greatest height equal to rather more than half the length ; left valve overlapping 

 the right at the antero-dorsal angle, beneath Avhich it is sinuated and forms a slightly 

 prominent beak (fig. 20); anterior extremity of the right valve evenly rounded, the 

 antennal notch deep and narrow; posterior extremity wider, rounded off, but strongly 

 angulated in the middle and again between that point and the dorsum ; dorsal margin 

 almost flat for the greater part of its length, but gently curved behind, ventral forming 

 a continuous gentle curve: seen from above the outline is elliptical (fig. 21), with 

 broad, slightly rounded or subtruncate extremities; lateral margins gently and evenly 

 arcuate, greatest width situated in the middle and equal to half the length. Surface of 



' Trans. Zool. Soc. London, vol. xiv, pt. iii,, 1897, p. 85 : "A Supplementary Eeport on the Crustaceans of 

 the Group Myodocopa, &c."' 



2e2 



