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entrusted to me by Professor Coutiere of Paris. The two specimens from Balikpapan differ 

 from the type species i" by the broader telson, 2° by the carpocerite being just as long as 

 the antennular peduncle, 3" by the more narrow shape of the dactylus of the small chela of 

 the male and 4" by the carpus of the 2"<i legs presenting a somewhat less slender form and 

 the 2""^ seo-ment being distinctly shorter than the i^t. These specimens are therefore described 

 as a variety of A. brevlrostris^ but they will perhaps prove to be specifically distinct, when 

 -we one day will be able to compare this variety carefully with specimens of the typical species. 

 The typical A. drevirostris from New Holland is, indeed, as far as I am aware, only known 

 by the descriptions of Olivier and H. Milne-Edwards and by observations of Coutiere and 

 myself, all derived from Olivier's type, for this rare species has seemingly not yet been found 

 back since it was described in the Encyclopaedic Methodique. 



The male is 45 mm. long, the female 62 mm. While in the female the rostrum reaches 

 just to the middle of the visible part of basal antennular article, it surpasses in the male very 

 slightly the middle; the rostral carina, which is strongly compressed and acute and separated 

 from the eye-hoods by rather broad and deep grooves, is traceable to the middle of the 

 carapace, more distinctly in the larger specimen, the female, than in the other. 



As results from the Table, the telson appears a little broader with regard to its 

 length than in A. drevirostris, but the telson of the male does not fully resemble that of the 

 female. In the female the posterior margin appears a little wider in proportion to the length 

 of the telson than in the male and in the male the posterior pair of spinules on the upper 

 surface are situated nearer to the anterior pair than in the female. 



The. inner antennae agree with those of the typical species and, both in the male and 

 in the female, the terminal spinule of the stylocerite is distinctly directed outward. In 

 both specimens the basicerite is armed with a small spinule at the lower side; the carpocerite, 

 both in the male and in the female just as long as the antennular peduncle, extends in the 

 male to the distal 3"^ or 4^'^ part of the terminal joint of the external maxillipeds, in the 

 female, however, just as far as in the typical species, namely to the middle of the joint; the 

 scaphocerite presents the same form and the same length as in the typical species. 



In the male the right cheliped is the larger. In both chelipeds the upper margin of 

 the merus ends in a small, acute spine ; in both legs one observes a small spinule near the 

 proximal extremity of the infero-internal margin, another similar spinule in the middle and a 

 somewhat larger, though also rather small spine near the distal extremity. The large chela is 

 21,5 mm. long and 8 mm. high, while the fingers are 8,25 mm. long; height of the palm at 

 the articulation of the dactylus 7 mm. The transverse groove behind the articulation of the 

 dactylus is well-developed ; granulation of the palm rather fine, outer surface of the fingers 

 almost smooth. 



Of the typical A. drevirostris the small chela of the male has been figured by Coutiere 

 in his important work: Les "Alpheidae", Paris, 1899, p. 230, Fig. 282, while I have figured 

 the dactylus (I.e. Fig. 16). The small chela of the male from Balikpapan, however, closely 

 resembles that of the male of A. distingtiendus de Man, a Japanese species which de Haan 

 has described under the name of A. rapax (J. G. de Man, I.e. Fig. 9); in the male from 



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