245 

 f i6. Synalpheus Charon (Heller). 



Alpheus Charon C. Heller, in: Sitzungsber. Kais. Akad. Wiss. Wien, Bd. XLIV, 1861, p. 272, 



Taf. Ill, Fig. 21, 22. 

 Syjialpkeus Charon H. Coutiere, Les Alpheidae, 1899, p. 264, Fig. 331, 332, 332bis and in: 



Alpheidae Maid, and Laccad. Archip. 1905, p. 873 and in: Proc. U. S. Nat. Museum, 



XXXVI, 1909, p. 90. 



Nee: Alpheus Charon J. G. de Man, in: Zoolog. Jahrb. IX, Abth. f. Syst. 1897, p. 743, 

 Taf. 35, Fig. 6^. 



Stat. 209. September 23. Anchorage oft" the south point of Kabaena-island. Reef, i not yet 

 full-grown specimen without eggs. 



Rostrum acute, spiniform, twice as long as wide at its base, reaching almost to the end 

 of first antennular article, with the margins straight and converging from the base to the tip ; 

 supraorbital spines also acute and pointed, one-third shorter than the rostrum, with the inner 

 margins concave and separated from the rostrum by broad interspaces; outer margins also 

 slightly concave. The supraorbital spines that are wider at their base than long, are, like the 

 rostrum, glabrous and directed slightly downward. Anterior wall of the front partly visible from 

 above, at either side of the rostrum. 



Second antennular article just as long as wide, one-fourth shorter than the visible part 

 of first article, third about as long as second ; stylocerite extending to the distal fourth part 

 of second article. The carpocerite, 3-times as long as wide, extends beyond the antennular 

 peduncle almost by the whole length of the third article ; lower spine of basicerite shorter than 

 the stylocerite, reaching almost to the middle of second antennular article. The outer margin 

 of the scaphocerite is sHghtly concave, the terminal spine which is not curved inward and 

 which is as long as the carpocerite, exceeds the rounded tip of the scale by one-fourth of its 

 length, while the scale is as long as the antennular peduncle. Superior angle of the basicerite 

 rounded, truncate. 



Telson 3-times as long as the posterior margin is wide, the outer angles of the latter 

 are acute, though not at all prominent; greatest width 2,1 -times that of the posterior margin, 

 which is rather prominent. Spinules of upper surface small, 0,14 mm. long, inserted not far from 

 the lateral margins ; proportion between the length of the telson and the distance of the anterior 

 pair from the posterior margin 2,1, proportion between the distances of both pairs from the 

 posterior margin 1,7. 



Merus of both chelipeds with a spiniform tooth at the apex of the upper margin. Large 

 chela 6,4 mm. long, 2,5 mm. high, fingers 1,85 mm. long; proportion between the length and 

 the height of the palm 1,8, proportion between the total length and the length of the fingers 

 3,45. A small, obtuse tubercle at the far end of the palm. The small chela has the following 

 relative dimensions: fingers i; total length 2,75; height 0,975, the chela 2,S2-times as long 

 (2,2 mm.) as high (0,78 mm.). Proportion between the length of both chelae 2,9. Merus of 

 second legs 4,6-times as long as wide. The first segment of the carpus is i mm. long, 4-times 

 as long as thick at the distal end and twice as long as the fifth, while it appears but a 

 little shorter than the sum (1,1 mm.) of the four following segments. The chela, the fingers of 



113 



SIBOGA-EXPEDITIE XXXIX a'. 32 



