CEtrSTACEA OF THE MERaUI AECHIPELAGO. 257 



racters it forms a remarkable transition between the two hitberto 

 known species of the genus Gehiopsis, Viz. G.niticla,K. M.-Edw.j 

 from the Cape Yerde Islands, and G. Darwinii, Miers, from the 

 seas of Australia *. 



This new species may be distingtiisbed from G. Darwinii, (1) 

 by the comparatively longer peduncles of the internal and external 

 antennae, (2) by the meropodites of the chelipedes being armed 

 with a row of minute, acute spinules along their infero-internal 

 margins, (3) by the carpopodites of the clielipedes being armed 

 with two strong spines, and (4) by the shape of the last pair of 

 ambulatory legs, which more resemble those of a true Gehia. 



G. mtermedia may be seen at first sight to differ from G. oiitida 

 by the mach shorter peduncles of the internal and external 

 antennae, and by many other characters. In its general appear- 

 ance, however, it much resembles that species, not only as regards 

 the body, but also in the shape and the structure of its legs, 

 which is seen on comparing it with the figure of that species 

 in the ' Nouvelles Archives.' The front is very short, horizontal, 

 not at all deflexed, and projects but little beyond the short thick 

 eye-peduncles, of which only the corneae are visible when seen 

 from above. The front is armed with four equidistant, short, 

 equal, and acute spinules on its anterior margin. The front 

 and the larger anterior half of the gastric region are densely 

 covered with tufts of short hairs, between which they are 

 armed with many acute spinules and granules ; the lateral 

 margins of the gastric region are also armed on each side 

 with a row of 14-15 small acute teeth, which gradually increase 

 in size anteriorly, so that the anterior teeth are much larger 

 than the posterior. The cervical suture is broad and deep, and, 

 on each side, the gastric region is bordered by a rather deep 

 longitudinal groove, immediately below and parallel to the 

 rows of small teeth which issue posteriorly into the cervical 

 suture. Behind the cervical suture the dorsal surface of the 

 carapace is smooth in the middle and a little rugose on the 

 sides; its posterior margin is fringed with short hairs. The 

 segments of the postabdomen are smooth, but somewhat hairy 



* Miers (Zoology of the Voyage of H.M.S. ' Alert ') mentions another species 

 from the Australian seas, which he proposes to designate Gebiopsis BowerbanMi, 

 if specifically distinct ; this form, however, seems only to differ from G. Dar- 

 winii in the armature of the front. 



LINN. JOUllN. — ZOOLOGY, VOL. XXII. 17 



