186/.] MR. J. Y. JOHNSON ON NEW CRUSTACEANS, 897 



plate, is shorter than either the sixth segment or the lateral swim- 

 ming-plates. It is narrow and pointed, furnished with a deep lon- 

 gitudinal groove on its upper surface and a small marginal tooth at 

 each edge, nearer the hase than the posterior extremity. The lateral 

 swimming-plates are narrowly oval, and those of the inner pair are 

 marked on their upper surfaces by two longitudinal ridges, those of 

 the outer pair by four similar ridges. There is a tooth at the outer 

 side of the latter pair of plates, not far from the posterior extremity. 



The imperfect condition of the single individual obtained prevents 

 me describing the rostrum, the eyes, and the filaments of both pairs 

 of antennae. It may be stated, however, that the rostrum appears 

 to have carried a crest at each side, that the longer filament of the 

 superior antennae is thickened at the base and setiform above, whilst 

 the shorter filament of these antennae is setiform throughout, and 

 that the filament of the inferior antennae is compressed below. It 

 may be further stated that the median carapacial crest appears to 

 have carried a small tooth at a point distant about three-tenths of 

 the length of the carapace from the anterior border. 



The species is named in compliment to my friend Mr. Henry 

 Woodward of the British Museum, well known for his labours 

 amongst fossil Crustacea. 



The following are the dimensions of the specimen, which is now 



in the British Museum : — . , 



inches. 



Total length from anterior border of carapace to end 



of caudal plates 6^ 



Carapace, length of side 2| 



, height 1 



, thickness | 



Lamellar palp of inferior antennae li 



Jaw-feet, length of external pair l| 



Ambulatory legs, length of fourth pair 1|- 



, length of third pair 14 



, length of first pair 1 g 



False feet, length of second, third, and fourth pairs . . 1| 



Pen^us edwardsianus, sp. n., $ . 



Colour a brilliant crimson, with an obscure fuscous cross band on 

 the hinder part of the carapace and on each abdominal segment. 

 Carapace somewhat compressed, shining, hairless, its surface un- 

 armed, with a low obtuse median crest commencing near the poste- 

 rior border. This crest rises gradually, and projects in front as the 

 rostrum, which is long, pointed, compressed, rather slender, and 

 curved obliquely upwards for its anterior half. At each side of its 

 basal portion there is a rounded crest. It extends beyond the pe- 

 duncles of both pairs of antennae, and beyond the lamellar palp of 

 the superior antennae ; but it is considerably shorter than the cara- 

 pace. It carries two small teeth — one a little in advance of its base, 

 and a second further in front, separated from the first by a distance 

 equal to one-fourth of the length of the rostrum. About the same 



