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PROCEEDINGS OF THE NATIONAL MUSEUM. 



VOL. XXXVI. 



nular article, and is sometimes as wide as the lateral spine; the latter 

 is equal to that of the basicerite, or is very slightly shorter; the 

 carpocerite exceeds the antenniile by 1^ times the length of the distal 

 article ; it is concave exteriorly and 6.5 times longer than wide, being, 

 in consequence, more slender than in S. grmnpvsi and S. parfaiti 



The proportions of the large chela are: Fingers 1; total. length 

 3.3; height 1.3 in the male; that of the female is more stocky, the 

 last dimension reaching 1.4; T. L. : H.=2.3:2.5. By its form, by 

 the spine, which is directed obliquely downward, and is on the an- 

 terior border of the palm, this chela is much like that of S. grampusi 



Fig. 39. — Synalpheus pandionis. a, frontal and antennal kegion ; c, carpocerite, 



MALE and female; K, large chela; k' , SMALL CHELIPED OF FIRST PAIR; I, FOOT OF 

 SECOND PAIR ; m, FOOT OF THIRD PAIR, MALE AND FEMALE; t, TELSON. 



The small chela is to the large as 1 to 3, in both sexes; it is con- 

 sequently smaller than in specimens of S. granrpHfii of the same size; 

 the proportions are as follows: Fingers 1; total length 2.4; height 

 0.72; it is therefore more slender than in S. grampvfii. 



The second pair has the same proportions as in 8. grdmpush but 

 it is a little more slender (proportion about 1: 1.08) especially in the 

 female. 



The third pair are similar; the meropodites are equal in two spec- 

 imens, one of S. grampusi and one of S. pandionis, of the same length, 

 but the proportion of the length to the width is 3..3 in the first case, 

 3.8 in the second, even more pronounced in the male; in the female 

 of S. pandionis this proportion is reduced to 3.7, 



