66 PERCY SLADEN TRUST EXPEDITION 
in the early post-larval stages. That this extraordinary development also takes place in 
Notostomus admits of very little doubt. Smith has, indeed, remarked that in an example 
of NV. robustus, 53 mm. in length, the rostrum is very much longer than in two other 
specimens measuring 135 and 150 mm. respectively. In the following synopsis the 
characters employed are drawn for the most part from the carination of the carapace ; 
there is reason to believe that this feature does not alter during the course of late post- 
larval growth. 
Partial synopsis of the species of Notostomus*. 
I. ‘he lateral carina of the rostrum terminates near the post-orbital carina but is nut continuous with it. 
A. In the posterior half of the carapace the customary short carina immediately below the post-orbital is 
absent ; there is no post-antennal carina ... : aon sib ace oa Sragilis, Faxon 
B. A short carina is present in the posterior half of the carapace immediately below the post-orbital ; a 
post-antennal carina is distinct, at least in the hepatic region. 
1. The post-antennal carina is indistinct behind the ridge separating the branchial and hepatic 
regions ... sos as 06 : ie ot Bis abe vescus, Smith. 
2. The post-antennal carina is aves ond divtitact throughout almost the whole length of the 
carapace. 
a. The post-orbital carma curves downwards in its extreme anterior part, but behind this is 
practically straight. 
i. The dorsal ridge of the carapace, viewed laterally, is straight over a considerable part of 
its median portion... Sie “els ae ae: 300 ne japonicus, Bate. 
ii. The dorsal ridge of the carapace is very strongly arched in lateral view, 
patentissimus, Bate; westergreni, Faxon ; longirostrist, Bate. 
b. The post-orbital carina curves downwards in its extreme anterior part, and behind this is 
descendant to the upper limit of the branchio-hepatic ridge and ascendant from this point 
to the posterior margin ... as ae 300 906 S60 go robustus, Smith. 
II. The lateral carina of the rostrum is continuous with the post-orbital. 
A, There is no carina in the posterior half of the carapace immediately below the post-orbital, 
gibbosus, A. M. Edw. ; elegans}, A. M. Edw. ; murrayit, Bate. 
&. A short carina is present in the posterior half of the carapace immediately below the post-orbital, 
perlatus, Bate; brevirostris, Bate. 
13. Notostomus perlatus, Spence Bate (Plate 7, fig. 10). 
Notostomus perlatus, Spence Bate, Voy. H.M.S. “Challenger,” xxiy., Crustacea Macrura, 1888, p. 831, 
pl. 124, fig. 2. 
1 Notostomus brevirostris, Spence Bate, ibid., p. 832, pl. cxxxiv., fig. 4 
May 17,1905. N. of Chagos Archipelago; 4° 16’S., 71° 53’ E. 1200—0 fms. ; one 
male, 138 mm. 
* For descriptions of the species the following papers should be consulted : 
A. Milne Edwards, Ann. Sci. Nat. Zool. (Sér. 6), xi. 1881, art. 4, p. 7 and Recueil, figs. Crust. nouv. 
ou peu connus, 1883, pls. 19, 40. 
Smith, Ann. Rep. U.S. Fish Commission for 1882 (1884), p. 377 and id. for 1885 (1886), p. 72. 
Bate, Voy. H.M.S. “Challenger,” xxiv. Crust. Macrura, 1888, p. 824. 
Faxon, Mem. Mus. Comp. Zool. Harvard, xviii. 1895, p. 170. 
Notostomus corallinus, A. M. Edw., does not seem to be correctly referred to this genus. 
7 The position of this species is doubtful. 
