REPORT ON THE CRUSTACEA MACRURA. 811 



Habitat.— Station 205, November 13, 1874; lat, 16° 42' N., long. 119° 22' E.; off' 

 Luzon, Philippine Islands ; depth, 1050 fathoms ; bottom, blue mud ; bottom temperature, 

 37°. Six specimens ; two males, four females, one laden with ova. Trawled. 



Station 195, October 3, 1874; lat. 4° 21' S., long. 129° 7' E; off Banda Island; 

 depth, 1425 fathoms; bottom, blue mud; bottom temperature, 38°. One specimen, 

 female. Trawled. 



Station 237, June 17, 1874; lat, 34° 37' N, long. 140° 32' E.; near Yokohama, 

 Japan; depth, 1875 fathoms; bottom, blue mud; bottom temperature, 35°'3. One 

 specimen, female. Trawled. 



Station 176, August 15, 1874; lat, 18° 30' S., long. 173° 52' E. ; off the New 

 Hebrides; depth, 1450 fathoms; bottom,. Globigerina ooze ; bottom temperature, 36°"2. 



All the specimens from Station 205 were much damaged, and none of them had any 

 of their appendages preserved, so that I am only able to determine the distinctness of the 

 species by the length, form, and armature of the rostrum, and by the third somite of the 

 pleon being posteriorly produced to an obtuse point over the dorsal surface of the next 

 succeeding somite. 



The ophthalmus is less globular than in Nematocarcinus undulatipes. 



The peduncle of the first pair of antennse is considerably shorter than the rostrum, and 

 the scaphocerite of the second pair reaches beyond the distal extremity of the rostrum. 



Observations. — The ova are ovate in form, very numerous, and in an advanced stage 

 of development, Three of the specimens are undoubtedly of the same species and are 

 females, but two of the others are males and vary in size and other important details. 

 Their lengths are respectively 88 mm. and 75 mm.; they differ also in the depth of the 

 carapace at the genital region, which is 12 mm. and 10 mm. respectively. The length of 

 the rostrum also differs; in one it is 13 mm. and in the other 11 mm., it is more curved 

 upwards in the larger and typical specimen, and the number of teeth on the upper surface 

 is eighteen, the lower margin is free from teeth from the base to the apex, while in 

 the smaller there are twenty-three teeth on the upper surface and a small tooth on the 

 lower near the apex, the rest of the under surface in both forms being fringed with hairs. 



It would therefore appear that in the series of teeth on the dorsal crest, a uniform 

 number is certainly not an essential feature of specific distinction, and I am not certain 

 that the solitary tooth on the lower surface in the smaller specimen is a fixed condition, 

 inasmuch as in certain undoubted species, as Nematocarcinus undulatipes, there are 

 indications of a tendency to vary in this. But what drew my attention first to the 

 possible distinction of specific condition is the form of the plates on the ventral surface 

 of the males, and that of the inner branch of the first pair of pleopoda. The ventral 

 plates are well developed in each, but the posterior plate in the large form has the lateral 

 processes less developed than in the smaller, and the inner branch of the first pair of 



