177 



the orbital spine is described as "a strong tooth", and then follows "the infero-lateral angle is 

 also armed with a short tooth", and on p. 634 it says that this "short" tooth is long! It is 

 also remarkable that the author compares both Heteroc. dorsalis and Ilcteroc. Alphonsi with 

 Hctcroc. oryx A. M.-Edw., but not inter se, and one becomes inclined to think that the 

 descriptions of the two species have been made a long time after one another and that 

 the author, when describing the second species, had forgotten the description of the former. I 

 not succeed in hnding any good character, by which Heteroc. AlpJionsi should differ from 

 Heteroc. dorsalis. Nevertheless, according to Alcock, the rostrum of Heteroc. Alphonsi should 

 measure indeed "about I'/^-times the length of the carapace proper" in the adult animal and 

 it should be armed dorsally with nine or ten teeth, two of which should stand on the 

 carapace, and ventrally with ten to thirteen, but for the rest also Ai.cgck's description 

 mentions no character, by which both forms could be distinguished. Heteroc. Alphonsi Bate 

 must therefore probably be considered as a variety of Heteroc. dorsalis, distinguished by the 

 longer rostrum and by the upper margin being as a rule only armed with 9 or 10 teeth, two 

 of which stand on the carapace. 



Table of Measurements in millimeters. 



Length of carapace 

 Length of rostrum. 



Rostral formula 



Length of carapace 

 Length of rostrum. 



Rostral formula 



Length of carapace 

 Length of rostrum 



Rostral formula . . 



Length of carapace 

 Length of rostrum. 



Rostral formula 



Length of carapace 

 Length of rostrum. 



Rostral formula. 



X" 1—6 Stat. 38, 

 Stat. 45, N" 7 — 1 1 adult 

 females from Stat. 122; 



N" I and 2 males, N" 3 — 6 females, N" 3 

 males, the rest young: N" 19 and 20 Stat. 

 N" 24 Stat. 178; X» 25 Stat. 211 ; N" 26 



SIBOGA-EXPEDITIE XXXIX a". 



53 

 27,5 



35 



3 

 1 2 



and 4 with eggs; X" 7 — iS 

 85; X" 21 — 23 ova-bearing 

 Stat. 267; X" 27 Stat. 297; 

 23 



