CARCINOLOGICAL STUDIES. 5 



separate the two regions from one another. In the male 

 specimen a shallow transverse impression separates still the 

 cardiac from the intestinal region, but in the larger female 

 even this impression is almost indistinguishable. The two 

 furrows which border the third lobe of the antero-lateral 

 margins, are as short as in A. Richtersii, and the furrow 

 which extends along the upper margin of the orbits and 

 the two anterior antero-lateral lobes, quite resembles that 

 which exists in A. Richtersii. 



The somewhat prominent front is about as narrow as 

 in the other species, and divided by a narrow incision in 

 two rounded lobes ; these lobes are directed obliquely back- 

 ward and are more distinctly emargiuate towards 

 their external angles , which are dentiform and scarcely 

 separated from the internal angles of the orbits. The eye- 

 peduncles and the orbits resemble those of the other species. 



The antero-lateral margins are a little longer than 

 the postero-lateral ones , but they are equal in length in 

 the other species. They are rather indistinctly divided into 

 four lobes, the first of which is only a little longer 

 than the second: the first antero-lateral lobe of ^ . i?w;/itersM, 

 however, is nearly as long as the three other lobes taken 

 together. The third lobe is separated by more distinct 

 notches from the second and the fourth, than the first 

 lobe from the second. The third lobe measures two thirds 

 of the length of the second , and is slightly rounded and 

 prominent. It ought to be observed that in the younger 

 male specimen the antero-lateral margins appear to me to 

 be comparatively a little longer than those of the adult 

 female , and that the third lobe of the former projects a 

 little more outward laterally than the fourth , whereas in 

 the female the fourth lobe projects more outward than 

 the third. As regards the granulation of the cephalothorax, 

 both species almost agree with one another, and the upper 

 surface is covered with very short hairs which are also 

 inserted at the base of the granules. 



The under surface of the cephalothorax is everywhere 



Notes from the Leyden IMuseutu, Vol. XIII. 



