Mr. E. J. Miers on Malaysian Crustacea. 229 



the next joint enlarged but more elongated and less dilated 

 than in that genus. Ischium-joint of outer maxillipedes small 

 and narrow ; merus-joint somewhat produced at its antero- 

 external angle, as in Othonia. Anterior legs (in the male) 

 small and slender ; palm smooth and not dilated, twice as long 

 as the ringers, which are excavated on their inner margins 

 towards the apices, which, however, are acute. Ambulatory 

 legs of moderate length. Postabdomen (of male) with ail the 

 segments distinct. 



This interesting transitional form must be placed in the sub- 

 family Othoniince (as characterized in my recent revision of 

 the Maioidea, a group hitherto restricted to the single West- 

 Indian genus Othonia). From that genus it is distinguished 

 by the more elongated carapace, which is not armed with 

 lateral spines, the more distinct rostral spines, less dilated 

 third antennal joints, and non-dilated anterior legs of the 

 male. It is very distinctly related to Criocarcinus and Pseu- 

 domtcipjje in the family Maiidee ; the inferior hiatus of the 

 tubular orbits in Criocarcinus , however, is closed in Othonia 

 and Cycfocoeloma. 



Cyclocceloma tuberculatum^ sp. n. 

 (PI. XIII. figs. 1, 2.) 



Carapace armed with tubercles disposed as follows: — five 

 tubercles, of which the median is the largest, on the front of 

 the gastric region, and posterior to these four large rounded 

 elevations in a median series, viz. one on the gastric, one on 

 the cardiac, one on the intestinal region, and one on the pos- 

 terior margin ; there is a prominent rounded tubercle on each 

 hepatic region, and about four on each branchial region, of 

 which one is much larger than the rest. The spines of the 

 rostrum are subacute and separated by a narrow median 

 fissure. The slender palm or penultimate joint of the anterior 

 legs about equals the arm in length, aud is smooth, not com- 

 pressed or dilated ; the fingers are shorter than the palm. The 

 small terminal claw of the ambulatory legs is but slightly 

 incurved. Length 1| inch, breadth 1 inch. 



Amboina (an adult male). 



The single example has a short series of stiff curled 

 hairs on the front of the gastric and cardiac regions and 

 on the sides of the branchial regions. The first free an- 

 tennal joint is narrowest at base and dilated toward the distal 

 end, where it is about half as broad as long ; thus it differs 

 markedly from the slender form of certain species of Macro- 

 cceloma in the Pericerida?, to which this genus bears some ex- 

 ternal resemblance. In Macroctr/omo, moreover, the rostrum 



Ann. & Mag. X. Hist. Ser. 5. Vol. v. 16 



