;oi 



Aegeon Ratkbuni J. G. de Man, in: Tijdschr. d. Ned. Dierk. Vereeniging, (2) Dl. XVI, Afl. 2 

 and 3, 191S, p. 304. 



Stat. 8g. June 21. Pulu Kaniungan Ketjil. 11 m. Bottom coral. 1 male. 



The characters, mentioned by Miss Rathbun, are sufficiënt to distinguish this species 

 from A. orientalis Henderson, about which Stanlky Kemp lias lately furnished useful information 

 (Stanley Kemp, in: Records Indian Museum, Vol. XII, Part VIII, Calcutta 1916, p. 378). The 

 photograph in Miss Rathbun's paper is unfortunately not clear, so that new figures are given 

 and she also not made mention of the length. The male from Stat. 89 (Fig. 74, 74a) is 28 mm. 

 long, the rostral spines included (carapace 8 mm., abdomen 20 mm.). The two conical, subacute 

 teeth in which the rostrum (Fig. 7 \&) ends anteriorly and which are separated by a broad 

 interspace, reach to midway the short eyestalks; on either side at the base a somewhat smaller 

 spine occurs. The distance (0,5 mm.) between the line, long 0,72 mm., uniting the tips of the two 

 basal teeth and the line uniting those of the two apical teeth, is only one-fourth longer 

 than the distance (0,4 mm.) between the apices of the two anterior teeth. Of the 5 spines of 

 the median carina the middle one is the smallest. First or upper lateral carina 7-spined, second 

 armed on the left side with 9, on the right with 8 spines, thircl on the left side with 5, on 

 the right with 6 spines, including the antero-lateral spine; the spines of the 2 ml and 3" 1 row 

 diminish in size posteriorly. 



Antepenultimate thoracic sternum armed with a strongly compressed tooth, the acute 

 tip of which is directed forward ; the two last thoracic sterna are sharply carinated and the 

 carina terminates anteriorly in a small sharp tooth. 



The abdomen agrees also with Miss Rathbun's description, the following may still be 

 added. The upper surface of the median crest on the 2 nd somite is slightly grooved longitudinally. 

 the median crests on the 3 rd and 4 th are flattened above, finely punctate, that of the 4 th shows 

 moreover an oval impressed point near the anterior extremity and this carina ends posteriorlv 

 in a sharp tooth. Submedian crests of 5 th somite entire. Telson 6,2 mm. long, little shorter 

 than the carapace and hardly more than one-fifth the entire length ; it is a little longer than 

 the uropods, deeply grooved longitudinally and the lateral margins of the upper surface are 

 furnished with two pairs of microscopic spinules, of which the anterior pair is placed just in 

 front of the middle, the posterior nearly at the posterior fourth. 



The pleuron of the i st somite is truncated inferiorly with rounded posterior margin-, ot 

 the two lateral carinae on each side of the 2 nd somite the lower forms the boundary between 

 tergum and pleuron, like on the 5 th and as also does the lower of the three carinae of the 4 th 

 somite; the pleuron of the 2 nd is bluntly angulated or almost rounded inferiorly and from each 

 of its rounded lateral margins an obtuse ridge runs backward respectively forward and curving 

 downward; 3 ld and 4" 1 pleura truncated with rounded, posterior margin; 5 th pleuron rounded and 

 armed posteriorly with 2 small spines, of which the larger upper is placed on the level of the 

 upper lateral carina. 



First abdominal sternum with a rather small, compressed tooth in the middle line, the 

 acute apex of which is directed forward; 2 nJ with a similar tooth, though smaller; following with 

 a still smaller and obtuse tooth. 



