CB.TJSTACEA OF THE MEKGUI ABCHIPELAGO. 213 



Porcellana Lamarckii, Milne-Edwards, Hist. Nat. Crustaces, t. ii. p. 251, 

 var. {nee Porcellana Lamarckii, Leach). 



Six fine speeimeas of this species were collected at Owen 

 Island. 



I have compared them with a typical specimen of this species, 

 kindly sent me by Dr. C. Koelbel, of the Imperial Museum 

 of Yienna, where the typical specimens of the ' Novara ' Expedi- 

 tion are preserved. 



The cephalothorax is flattened, and is quite as long as it is broad ; 

 its upper surface is punctate in the middle and posteriorly, and is 

 marked with faint transverse striae anteriorly and towards its 

 lateral margins. The front is triangular, with the apex rounded 

 and subconcave above ; it presents a mesial furrow, and a shorter 

 oblique one on each side, terminating at the internal angle of the 

 orbits. The front is separated from the gastric region by a 

 slightly elevated transverse crest, interrupted in the middle by 

 the mesial frontal furrow. There is a faint cervical suture 

 separating the gastric region from the rest of the upper surface. 

 There is no epibranchial spine. The lateral margins are slightly 

 cristate anteriorly, the carinas extending to nearly the middle 

 of the branchial regions. The antepenultimate joint of the 

 peduncle of the external antennae is provided with a small trans- 

 verse crest. 



The anterior legs are subequal. The arm has a blunt tooth at 

 the distal end of the anterior margin and the external * margin 

 of the under surface is armed with a small spinule about its 

 middle. The wrist is nearly as long as the carapace and thrice 

 as long as broad ; its anterior margin is armed with three acute 

 teeth, the first at the proximal end, the second a little before 

 the middle, and the third as far distant from the second as the 

 second is from the first. The obliquely rugose posterior margin 

 of the wrist is prolonged at its distal end into a rather acute 

 spine. The hands are much depressed and the inner borders of 

 both fingers are densely hairy. The anterior half of the upper 

 surface of the wrist is covered with flattened granules, which 

 gradually pass into small, curved, transverse, squamiform lines afc 

 the posterior half; these granules and lines are bordered with 

 minute hairs. The upper surface of the hands is covered with 

 similar, flattened, piliferous granules and squamiform lines. 



* The external margin is that which artionlates with the wrist. 



