16 DE. J. Q. DE MAN ON THE PODOPHTHAIiMOTJS 



eacli pair, meet one another posteriorly at the tubercle of 

 the posterior cardiac region. The anterior one of these two 

 tubercles, that lies on the mesobranchial region, is rather acute 

 in a. Pleione, and the posterior, though also blunt and obtuse, 

 is nevertheless more prominent in Herbst's species. The 

 epibranchial lobes, which are situated on each side of the 

 cervical suture, are provided in -ff. Silgendorfi each with two 

 small, little prominent, obtuse tubercles, lying behind one 

 another ; in S. Pleione these two tubercles are conical and acute. 

 Immediately behind the external angles of the orbits a small denti- 

 form, rather obtuse tubercle is found on the hepatic region of the 

 cephalothorax, wbich also occurs in S. Pleione. The lateral 

 sides of the upper surface of the cepbalothorax are moreover 

 armed in our species, as in Pleione, with some small dentiform 

 tubercles, which are situated behind the tubercles of the epi- 

 branchial and hepatic regions and the bases of the legs, close to 

 the latter. One of these dentiform tubercles is found, in both, 

 species, quite above the base of the chelipedes ; behind this 

 tubercle in S. Silgendorfi four small dentiform tubercles occur, 

 whereas in H. Pleione there are only two. I may add that these 

 four tubercles are arranged rather irregularly and that they 

 are often of a somewliat different size. Between the external 

 angle of the anterior margin of the buccal cavity and the denti- 

 form tubercle, which is found above the base of the anterior 

 legs, in botb species, two other dentiform tubercles occur, the 

 anterior of wMch is twice as broad as the posterior. 



The spines of the rostrum are comparatively a little longer than 

 those of a. Pleione (Dr. Hilgendorf informs me that the rostral 

 spines have been drawn too long in Herbst's figure of H. Pleione 

 (pi. Iviii. fig. 5). In the male of our species the proportion of 

 the length of the cephalothorax to the distance of the two 

 parallel imaginary lines, which unite respectively the tips of the 

 rostral spines and the anterior angles of the supraorbital margins, 

 is as 15 to 11 4^ ; in the female individuals this proportion is as 15 

 to 71. The rostral spines are thus comparatively shorter in the 

 female ; but I may observe that this condition may perhaps be 

 ascribed to the younger age of the female specimens, which are 

 much smaller than the male. The rostral spines are quite as 

 divergent as those of H. oryx (Nouv. Arch, du Museum Hist. JNat. 

 t. viii pi. 14. fig. 1). In H. Silgendorfi the rostral spines are 

 directed nearly horizontally forward, so that they make a very 



