*s RIJKS MUSEUM VAN NATU URLIJKE HISTORIE — LEIDEN. 205 



belonging to Ses. lafondi, the longitudinal keel is indeed present on the 
mobile finger, but on close inspection this keel is transversely 
striated, so that it is divided into about 25 parts, each of which is 
about 3 times as long as broad; the keel itself occupies only the proxi- 
mal half of the finger. Now, in the large Q of Ses. lafondi I have 
shown (p. 167), that the keel is somewhat longer, but exhibits at its 
distal end some detached portions, separated by a few transverse striae 
from the rest. Thus the gradual disappearance of these striae in Ses. 
lafondi may he ascribed to age, but their presence in the young Q is, 
in my opinion, a prove as to the specific identity of Ses. lJafondi and the 
subspecies of Ses. taeniolata here described. 
That in the Q a granulated row at the upper border of the palm 
takes the place of a pectinated crest on the same place in the © is of 
frequent occurrence in Sesarma, and the same may be said about the 
presence or absence of a transverse granular row at the inner surface 
of the palm. 
As to the deep and concave median sinus in the free margin of the 
front, the transverse tubercle on each lobe of the latter ') and the nar- 
row groove separating the inner postfrontal lobes, in comparing Pl. XV 
Fig. 1 with the textfigure 5 there is, in my opinion, nothing at variance 
with the view here expressed. And yet I prefer, in spite of all these points 
of resemblance, and of the fact, that the co of Ses. lafondi has never 
been observed, but that, now, this species is caught together with the 
new: subspecies crebrestriata of Ses. taeniolata, to regard the latter as a 
distinct subspecies, as long as no larger material is at hand. 
The following measurements may serve to elucidate the close rela- 
tionship of the typical Sesarma taeniolata with the subsp. crebrestriata 
and with Ses. lafondi. 
In order to facilitate the comparison I have chosen specimens of ap- 
proximately the same size. 
Dimensions: . 1 2 3 4 
cf Ss S 2 
Distance between external orbital angles 30.5 30°-— 29.— 28.5 mm. 
a epibranchial teeth. . 30.75 29.— 28.5 28.— , 
eaadth of carapace at hind part. Shy 20:0) = 210.0) Gomme gota) 
(above base of penultimate pair of legs) 
Posterlor-marein Of carapace <=.) 12.75 13.5, ta 1o.5- 7, 

1) In the young @ of Ses. dafondi (see p. 167) from Deli I have described a flattened and 
shallow median sinus in the free margin of the front, and the transverse tubercle on each pro- 
jection is replaced by two large granules, so that in this respect the specimen approaches the 
typ. Ses, taeniolata. 
