Plate 9. Fig. 1.

Description.—Carapace elongately ovate; gently curved dorsally, more strongly curved ventrally; anterior margin deeply serrate. Abdominal segments attenuated and inwardly curved towards the posterior part of the carapace; distal extremity uncinate. Abdominal segments approximately six, but actual sutures obscure. The proportionate length of the carapace slightly longer than that of the abdominal region. Height of highest part of carapace equals one-third its length. Extremity of abdominal series probably in the form of blunt stylets. Surface of carapace longitudinally and obliquely wrinkled.

Dimensions.—Entire length of carapace and abdominal region, 24 mm.; length of carapace, 14.25 mm.; height of carapace, 4.3 mm.

Observations.—This form differs from known species of Hymenocaris in its greatly elongate carapace, but the relation of the abdominal segments to the carapace warrants its inclusion in that genus. In general appearance it compares with some elongately extended varieties of H. vermicauda Salter (see Jones and Woodward, 1892, pl. xiii, fig. 4). In the ragged denticulated anterior margin, the specimen shows an affinity with Rhinopterocaris, but otherwise it is quite distinct from that genus. H. bensoni is named in acknowledgment of Dr W. N. Benson's courtesy in placing these specimens in my hands for description.

Locality.—No. 139. Loc. 3. Preservation Inlet, New Zealand.

Horizon.—L. 3.