REPORT ON THE CRUSTACEA MACRURA. 843 



margin being strengthened by a narrow ridge which terminates in a small but sharp tooth 

 somewhat short of the distal extremity of the squamous portion ; the peduncle has two 

 joints beyond the articulation of the scaphoceritc, of which the distal is the longer ; the 

 llagellum is Inst. 



The second pair of gnathopoda is long and robust ; the ultimate joint is broken, and 

 the penultimate is narrower than the antepenultimate, which is long, reaching as far as 

 the distal extremity of the peduncle of the first pair of antennae, and has the inner surface 

 for two-thirds of its length deeply excavate to leave room for the external oral append- 



- ; the basis carries a long ecphysis that reaches nearly to the distal extremity of the 

 meros. 



The first pair of pereiopoda is chelate but not more robust than the second pair of 

 gnathopoda. The second pair has the carpos and propodos longer than in the first 

 pair. The three succeeding pairs have the ischium and meros long, broad and flattened, 

 the carpos subcylindrical, the propodos long, and the dactylos long and styliform in the 

 anterior two pairs and short in the posterior. 



The pleopoda are biramose, the branches being flat and multiarticulate. In the first 

 pair the inner branch is reduced to a rudimentary condition and fringed with long hairs. 

 The posterior pair helps to form the rhipidura, and is imperfect in our only specimen. 



Observations. — This species is almost quite smooth dorsally, having only a small 

 narrow carina on the pleon and on the anterior portion of the carapace, the crest being 

 reduced to a minimum ridge. The teeth on the third, fourth, and fifth somites are 

 reduced to small points, but that on the third somite requires attentive observation to 

 detect, although, when present, it is generally the most conspicuous. 1 This species is the 

 same as that named Meningodora mollis by Sidney Smith, from which it appears to differ 

 only in having more numerous denticles on the frontal crest, and in the ophthalmopoda 

 reaching beyond the extremity of the rostrum instead of being shorter as in Smith's 

 figure and description, but the variation is so slight that it must be considered as being 

 specifically the same. 



The specimen is laden with a number of small round ova, all of which are attached to 

 the hairs that fringe the peduncles of the pleopoda. 



Hymenodora duplex, n. sp. (PL CXXXVI. fig. 3). 



Carapace anteriorly compressed to a rostral crest, that is not elevated above the line 

 of the dorsum, or produced beyond the level of the ophthalmopoda, and armed with 

 seven or eight small anteriorly directed denticles. Outer canthus of the orbit well 

 defined ; the first antennal tooth reduced to a minimum condition consistent with being 

 called a tooth ; second antennal tooth not large but clearly defined, projecting obliquely 



1 The dorsal teeth are too conspicuously represented on the plate. 



