297 



these two species are identical and, the abdominal pleura of A. viedinm being truncated 

 inferiorly ("Illustrations", I.e.), we may draw the conclusion that they are also truncated in the 

 type of A. propensalata. In the specimen from the Bay of Bima the abdominal pleura are 

 truncated and show the same characteristic form as in A. meditmi; also as resfards the 

 carination of the carapace this specimen agrees with this species, but, as there are in other 

 respects some slight difterences, it is considered as a new variety, for which the name of 

 hilarula is proposed. 



The male (Fig. 71, 71a, ~,\b) is probably young, for, measured in the middle line, the 

 carapace appears to be 7,7 mm. long, the abdomen 18 mm., the entire length 25,7 mm. from 

 tip of rostrum to tip of telson, whereas the male of A. propensalata attains a length of 34 mm. 

 The triangular rostrum (Fig. 7ir) that reaches only to the middle of the eyestalks, ends at the 

 tip in two small teeth, that are separated by a triangular notch ; the inner margin of each 

 tooth runs parallel with the outer margin of the other. The tooth on either side of the base of 

 the rostrum is rather small, not larger than the teeth at the apex; the distance (0,56 mm.), 

 measured in the middle line, between the line uniting the two teeth at the base and that which 

 unites the apices of the two apical teeth, is one-fifth shorter than the distance between the 

 tips of the two teeth at the base and the latter nearly 5-times as long as the distance between 

 the tips of the two apical teeth. The rostrum of A. propensalata is not cleft at the tip and 

 has a larger spine on either side of the base. 



The processes, with which the median, dorsal and lateral carinae of the carapace are 

 armed, are obtuse, blunt. The median carina consists of eight processes, that are moderately 

 prominent and of which the posterior is a little longer than the rest ; the tubercles of the dorsal 

 carinae, on each side of the middle, are more prominent, 8 on the left, 9 on the right and 

 the four, respectively five posterior tubercles are smaller than the five, respectively four anterior. 

 Orbital margin with two fissures, spine at the outer angle almost as long as the rostrum. The 

 large tooth or spine (Fig. 71^^) at the anterior extremity of the lateral carina extends as far 

 forward as the distal extremity of the basal antennular article and runs straight forward with 

 the tip slightly outwards; behind it are two obtuse teeth of which the anterior is shorter, though 

 more prominent than the posterior; the 7 or 8 processes of the posterior moiety of the lateral 

 crest are little prominent, especially the 4 or 5 posterior, and the anterior extremity is obtuse. 

 The serration of the supra-marginal carina, finally, is very obscure, like in the Challenger 

 type (Stanley Kemp, I.e.), so that Spence Bate even described it as smooth ; the 1 1 or i 2 processes, 

 by which it is compo.sed, become, however, perceptible when the carapace is looked at obliquely 

 from behind and the anterior extremity is blunt, little prominent. Branchiostegal angle subacute, 

 reaching as far forward as the eyes. Last three thoracic sterna sharply carinated in the middle line. 



The sculpturing of the abdomen is well-developed, prominent and resembles that of 

 A. media, except that there is no broad sinuous ridge on either side of the middle line of the 

 2"^ somite and extending obliquely throughout its length, but, like in A. pennata (Bate), two 

 tubercles separated by a vertical furrow that reaches to near the median 

 crest. The posterior sculptured part of the 2"'^ tergum (Fig. 71^) appears, measured in the 

 middle line, hardly half as long as that of the 3''<i, whereas it appears distinctly longer in 



SIBOGA-EXrEDITIE XXXIX a'. 3^ 



