12 ART. 2(1. M. YOKOYAMA. 



CRUSTACEA. 



11. Homolopsis japonicus n. sp. 

 PI. III. Fig. 4. 



A single specimen of carapace without appendages. 



Carapace ovately pentagonal, longer than wide, with the 

 front pointed. Branchial regions distinct, extending to a little 

 more than half the length of the carapace, approximately 

 triangular in shape with metabranchial lobes separated from 

 epibranchial and mesobranchial ones by a deep furrow. They 

 do not meet in the median line of the shell at the posterior 

 border, but are separated from each other by a broadly triangu- 

 lar field which is to be taken for the metacardiac lobe. Meso- 

 branchial and epibranchial lobes both separated from each other 

 and from the other portions by a more or less distinct furrow. 

 Epicardiac region elevated, shield-like in shape, with a tuber- 

 cular eminence on each side, so that the portion between these 

 eminences looks like a depression. Metagastric lobes distinct 

 each with a tubercle and extending obliquely forward and 

 laterally. Mesogastric lobe also distinct, broadly rhombic in 

 outline and furnished with a single large tubercle in the middle 

 and a long narrow median process reaching nearly to the front 

 margin of the shell. Hepatic as well as epigastric lobes each 

 marked by a tubercle. Protogastric and urogastric lobes not 

 well developed. 



The frontal margin of the carapace is not well preserved, 

 but seems to end in two short spines. The postero-lateral 

 corners are also not perfect, so that it is not possible to tell 



