Stuilii's on marine Ostracotls oil 



iiioro than half as long as this joint; it has a strong bend near the base (as shown in fig. 55, 

 ])1. 4, A. oblonga, (I. ^^'. MtlLLER, 1894). 



Mandible (tig. 9): — P r o t o p o d i t e: Basale: The backward pointing process 

 has the same number of bristles as in the female, but all of them except the dwarf bristles are 

 much weaker than those of the female and are almost smooth, with only short, fine, scarcely 

 visible hairs. In the middle of the dorsal side of this joint there is only one bristle both on the 

 right and the left mandible; this bristle is in most cases somewhat more than twice the length 

 of the corresponding bristle in the female. Endopodite: First joint: The shortest of the 

 three ventral bristles is furnished at the middle with fine hairs scattered on all sides; these are 

 not quite so long as the long secondary bristles on the two other of these bristles. Second joint: 

 This has three proximal bristles of somewhat different lengths; the longest is about half as long 

 as the main bristle a, the shortest is in most cases somewhat less than half the length of the longest. 

 The medial cleaning bristles are considerably longer and somewhat more weakly equipped 

 than those of the female. They are also somewhat more numerous; the following numbers were 

 observed: six bristles in a distinct lower row, three to five bristles in a sparse and sometimes 

 rather irregular upper row. To judge from its position the anterior bristle in the upper row 

 certainly corresponds to the bristle ,, close to the main bristle b" of the female. The end claw is 

 perhaps slightly shorter than that of the female. 



The f u r c a has nine claws, of which the six or seven anterior ones may be termed 

 main claws. The anterior ones are somewhat more decidedly bent than in the female (about 

 the same as in fig. 14 of A. curta). 



The lateral eyes are somewhat larger than those of the female. 



Remarks: — In all the samples in which more than one mature female occurred there Occurrence of 

 were to be found females with as well as without eggs or embryos: the first category was, however, 

 always in the majority. 



The male and the female juvenes of the first larval stage occurred in abcjut the proportion Propor/ian hctwoa, 

 3 : 1 in the sample collected on the l^t of March; in the other samples the male and the female "'" " '"" """ ' ' 

 juvenes of this stage were about equal in number or the males were about twice as numerous as 

 the females. In the second larval stage too the males were stated to be in the majority. 



Habitat: — Monaco: In the harbour, (t y p e - 1 o c a 1 i t y); depth about 10 m. ; 

 fine clay with detritus: 1. III. 1916: 3 mature males, 5 mature females and 25 juvenes in different 

 stages; R. M. S. 178 and 179. 8. III. 1916: 2 mature females and 20 juvenes in different stages; 

 R. M. S. 180. 5. IV. 1916: 1 mature female and 4 juvenes; R. M. S. 181. 19. IV. 1916: 2 mature 

 females and some juvenes in different stages; R. M. S. 182 and 183. (Auctor coll.) 



Type specimen on slides in the collections of the R. M. S. 



