428 



Stat. 231. November 14/18. Ambon-anchorage. Reef, i male and i ova-bearing female of 



medium size. 

 Stat. 234. November 19/20. Nalahia-bay, Nusa-Laut-island. 46 m. Bottom stony, i ova-bearing 



female. 

 Stat. 240. November 22 till December i. Banda-anchorage. Reef. 7 mostly young specimens, 



2 of which with eggs. 

 Stat. 301. January 30 — February i. io°38'S., I23°25'.2E. Pepela-bay, East coast of Rotti- 



island. Reef, i ova-bearing female. 



According to Dana A. pacificus attains a length of one and three-fourths inches (45 mm.), 

 but the largest specimen, taken by the "Siboga", an ova-bearing female from Stat. 93, is hardly 

 35 mm. long. In this species the females are already ova-bearing at a very young age, 

 so e. 0-. a female from Stat. 133, u^hich is 15,5 mm. long. In Dana's figure 5a the rostrum 

 appears very short, hardly reaching beyond the orbital hoods; as is shown, however, by the 

 numerous specimens collected by the "Siboga", the length of the rostrum is rather variable. 

 In the largest specimen from Stat. 93, like also in most other ones, the rostrum projects 

 horizontally forward almost to the end of first antennular article, presenting the same form as 

 in the figure 47 of Coutiere's quoted paper; in a somewhat younger specimen from the same 

 station the rostrum extends as far forward, but it is slightly turned upward and it appears 

 much narrower at its base; in a young specimen, finally, 18 mm. long, from Stat. 133, 

 the rostrum appears as short as in Dana's figure, but this is apparently an exception. The 

 rostrum proper carries at either side a few. four or five, fine, rather short hairs, like 

 in A. luacrochinis Richters, though in A. niacrochirus the hairs are longer and more numerous. 

 The rostral carina is low, rounded above and separated from the orbital hoods by narrow grooves. 



A. gracilidigihis Miers is, no doubt, identical with this species. According to the 

 measurements mentioned by Coutiere, the fingers of the small chela should be, in A. pacifims, 

 a little shorter in proportion to the palm than they appear in the figure 32 of PI. XXV of 

 my paper published in 1892 (I.e.), but in the young male, long 20mm., from Ambon the 

 proportion between the length of the chela and that of the fingers is 1,36, the fingers being 

 almost 3-times as long as the palm and leaving an interspace between them when closed, 

 whereas the palm appears but slightly longer than high. In the other specimens the small 

 chela agrees with the measurements and figures published by Coutiere. 



Alpheus pacificus Dana, one of the few species of the Edwardsii group, in which the 

 merus of the V*^ and 4"' legs is unarmed and in which the dactylus of the smaller chela shows 

 never the Balaeniceps-iorm, may easily be recognized by the shape of the rostrum, of the orbital 

 hoods, of the scaphocerite etc. 



Remarks. The species which has been described by Hilgendorf as A. pacificus (in: 

 Monatsber. Kon. Akad. Wiss. Berlin, 1878, p. 832) is a different form, in which the merus 

 of the third lees is armed with a tooth and in which the infero-internal margin of the merus 

 of the first pair of legs carries a spine. 



General distribution: Red Sea (Coutiere); Madagascar (Coutiere); Maldives and 

 Laccadives (Coutiere); Fiji Islands, Totoya (Miers); Double Bay, New South Wales (Nobili); 

 Campbell Island (Coutiere); Sandwich Islands (Dana, Miers). 



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