's RIJKS MUSEUM VAN NATUURLIJKE HISTORIE — LEIDEN. 449 



Upper margin of 5th abdominal somite slightly compressed, blunt, 

 though not carinate and, like in Lept. robusta Stimps., unarmed at 

 posterior extremity. Lower surface of 6th somite, which in a lateral view 

 appears twice as long as wide, armed on each side with a long, 

 slender, slightly curved spine, measuring one-fourth the length 

 of the somite, implanted, close to the lateral margin, at the posterior 

 third of the lower surface and reaching almost as far backwards as the 

 posterior extremity of the lateral margin: in Lept. robusta Stimps. one 

 observes here only 'a much smaller spine, implanted much nearer to the 

 posterior margin of the lower surface. Telson resembling that of Lept 

 robusta Stimps., but only two pairs of spines on the upper surface, be- 

 cause one of the two posterior pairs does not occur in this species. 



External maxillipeds resembling those of Lept. robusta Stimps., but 

 the terminal joint a little shorter in proportion to the penultimate. 



Thoracic legs substantially resembling those of Lept. robusta Stimps., 

 but of a more slender form. 



Meningodora S. I. Smith. 



The genus Meningodora S. I. Smith must be considered as identical 

 with the genus Acanthephyra A. M.-Edw. The oral appendages, indeed, 

 show quite the. same characters, also the legs, and, as regards its outer 

 appearance, the only species, Meningodora mollis S. I. Smith, from the 

 east coast of the United States, resembles Acanth. curtirostris W.-Mas. 

 and other species, in which the rostrum is short. I wish to propose it, 

 however, as a subgenus of Acanthephyra, for those species, in which the 

 integument is very thin, soft and membranaceous. 



Acanthephyra (Meningodora) Sibogae n. sp. 



Stat. 210a. Sept. 24. 5° 26' S., 121° 18' E. Entrance of Gulf of Boni. 

 1944 m. Bottom grey mud, upper layer more liquid and brown; pumice 

 stone. 2 specimens, probably female. 



Integument soft and membranaceous, like in Acanth. brevirostris 

 S. I. Smith and Acanth. rostrata (Sp. Bate). Carapace dorsally carinate, 

 the sharp carina presenting a little before the middle a slight depression, 

 from which the cervical groove proceeds forwards and downwards. Rostrum 

 one-fifth the length of the rest of the carapace, reaching to the middle 

 of 2nd joint of antennular peduncle, just as high at the level of the 

 orbital margin as long. Upper margin from midway between the cervical 



