122, 178 and 300, the rostrum agrees with that of the Challenger t\-pes. In the larger male 

 the rostrum is fj-dentate, two millimeters shorter than the carapace, as much recurved as in 

 Bate's figure and the y^ tooth of the gastric carina, which is but little farther distant from the 

 2"'' as the 2'"i from the P', is placed above the orbital margin. In a female without eggs, in 

 which the carapace is 31,5 mm. long, the rostrum is 34,5 mm. long and a little more recurved 

 than in the figure of P)Atk, three teeth stand on the carapace, but those of the pro.ximal half 

 of the upper margin are as far remote from one another as in the Challenger types, the 

 2'"' tooth of the rostrum proper being placed opposite the distal extremity of the antennular 

 peduncle; the rostrum is H-dentate. In the other adult specimens, however, the rostrum is 

 nearly as long as the carapace, more strongly recurved than in the Challenger types, 

 3 teeth stand on the carapace and the rostral formulae are i^-, H and ■^. The gastric carina 

 is quite conspicuous in this species and (Fig. 43^) bears a small tubercle posteriorly, not always 

 distinct, however, just before uniting with the transverse carina that joins the posterior extremities 

 of the post-ocular carinae and that runs parallel with the posterior margin. There is also on the 

 gastric carina a small elongate impression or pit, situated on the cardiac region, twice as far 

 distant from the 1"' tooth as from the described terminal tubercle. Like in Heteroc. laevigatus 

 Bate one observes, between the posterior extremity of the post-antennal carina and the postero- 

 lateral curved angle of the carapace, a short curved carina that fades away at the level of the 

 coxa of the 5''' pair of legs. The orbital spine reaches to the eyes, the strong branchiostegal 

 spine is flattened above, reaches as far forward as the other, sometimes even a little farther 

 and projects beyond the 2'"^' joint of the antennal peduncle, when the carapace is looked at 

 from above. 



Though the i^' and 2"'^' abdominal terga are described as smooth, it should, however, be 

 remarked that the i*' tergum (Fig. 43^) carries a transverse row of four more or less 

 prominent, small tubercles, two on each side of the middle; these four prominences 

 are not mentioned by Spence Bate, nor visible even in his magnified figure 2, but two small 

 similar prominences, that occur on each side of the 2°'^ somite, there where the tergum passes 

 into the pleura, are distinctly visible in the figure i 9- Concerning the following somites, it should 

 be remarked that the carina of the 3''"^ tergum is longitudinally fluted and that it is 

 not regularly arched in a lateral view, like in B.\te's figure 1 Q, but that the anterior half 

 makes a very obtuse angle with the posterior, which angle, however, is rounded and not 

 dentiform as in Heteroc. hostilis Faxon and affinis Faxon from the west coast of Central America, 

 and furthermore that the three spines slightly increase in length from the spine of the 

 Ty^^ to that of the 5''^ tergum. Exclusive of the spine the 5''' tergum measures two-thirds the 

 length of the 6"\ but inclusive of it the 6"' tergum appears but little longer than the 5"', 

 while the telson is as long as the 6''' and the 5''' somite combined, the latter without the spine; 

 6"i somite and telson dorsally grooved, telson with 3 pairs of dorso-lateral spinules besides those 

 at the tip, telson as long as the uropods. 



The stylocerite which is acuminate and provided with a basal process, reaches to the middle 

 or almost to the middle of the 2"'' antennular article, 3'^ article a little shorter than 2""^; inner 

 flao-ellum of the adult female as long as carapace and rostrum combined, outer a little shorter. 



