204 BULLETIN OF THE 



Heterocarpus hostilis, sp. nov. 



Similar to H. alphonsi Bate, from off the Philippine Islands and Japan, but 

 readily distinguished from that species by the stronger upward curve of the 

 rostrum, by the presence of but one tooth in the median dorsal line of the 

 carapace back of the base of the rostrum, and by the two spines on the third 

 abdominal segment. 



Length, 197 mm. ; rostrum, 70 mm.; carapace, including rostrum, 108 mm. 



Heterocarpus affinis, sp. nov. 



Very similar to H. hostilis, from which it differs in the following particulars. 

 The rostrum is much shorter; measured from the tip to the posterior limit 

 of the orbit, it about eqilals the rest of the carapace in length. There are 

 fewer teeth on its dorsal margin (five or six) ; the number of teeth on its lower 

 margin varies from six to ten. The median dorsal line of the carapace is more 

 convex, and it is armed, back of the base of the rostrum, with two acute teeth, 

 where there is but one tooth in H. hostilis. 



It bears a resemblance, further, to H. dorsalis Bate, collected by the " Chal- 

 lenger" in the Banda Sea, but it may be at once distinguished from the 

 Oriental species by its shorter rostrum and the presence of two median teeth 

 on the third abdominal segment. 



H. affinis and H. hostilis belong to different geographical areas. H. affinis 

 is the more northern form, found off Acapulco and Cape Corrientes, w'hile 

 H. hostilis was obtained in the Gulf of Panama. 



Station 3418. 660 fathoms. 13 specimens. 

 3424. 676 " 5 



" 3425. 680 " 9 " 



Family NEMATOCARCINID^. 



Nematocarcinus agassizii, sp. nov. 



The rostrum is one fifth longer than the rest of the carapace (in some small 

 specimens only equal to the rest of the carapace), slender, nearly horizontal 

 for the basal two fifths of its length, the remaining portion gently upturned and 

 ending in a very acute point; its upper margin is continued backward in the 



