by a series of both sexes from the Gulf of Siam in the collection of the Copenhagen Museum 

 and which I propose to describe elsewhere. It is very closely allied to B. arenosa Goodsir. 



Occurrence. Station 37. Plankton. One specimen. 

 Station 41. Plankton. One specimen. 



Cyclaspoides. 

 I . Cyclaspoides sp. 



A single adult male specimen belonging to this genus was discovered by Prof. Sluiter 

 in the atrial cavity of a species of Tunicate from Station 271, 1788 metres. The specimen is 

 considerably damaged but it resembles ver}^ closely C. Sarsi of Bonnier (Ann. Univ. Lyon 

 XXVI, Campagne du "Caudan", p. 530). As the adult male of that species has not yet been 

 described it seems inadvisable to venture on a more precise determination of the present 

 specimen since the characters in which it differs from the females and immature males of 

 C. sarsi might possibly be sexual differences. The most obvious of these is the greater length 

 of the uropods which considerably exceed the length of the last somite. 



The occurrence of the specimen in the atrial cavity of a Tunicate may have been 

 accidental. It has the appearance of having suffered partial digestion, the greater part of the 

 soft tissues having disappeared. 



Family VAUNTOMPSONiiDyE. 

 Heterocuma. 



I. Heterociiina {}) Weberi n. sp. Plate I, figs. 7 — 12. 



Description of Male. Total length 28,6 mm. 



The general form is elongated and slender. The carapace is small, scarcely one-fifth of 

 the total length, its vertical height a little less and its transverse width a little more than 

 one-half its length. Seen from above it is oval in shape, not much narrowed in front nor behind 

 and with the greatest width a little in front of the middle. The po.sterior half of the dorsal 

 surface is rounded from side to side but the anterior half is raised into a prominent crest, the 

 outline of which is convex with a slight concavity at the base of the ocular lobe. Pseudorostrum 

 very short, slightly upturned and bluntly rounded as .seen from the side. Antero-lateral margin 

 slightly concave without any distinct antennal notch. Antero-lateral angle obtuse. The ocular 

 lobe long and narrow^ reaching quite to the extremity of the pseudorostrum, slightly expanded 

 distally, where two large but indistinctly defined corneal areas can be made out. There is no 

 ocular pigment. The surface of the carapace anteriorly is beset with minute spiniform points 

 turned forwards; posteriorly, it is smooth. 



The thoracic somites diminish very gradually in width and in vertical height from before 

 backwards and the anterior abdominal somites are but little lower and narrower than the 

 posterior part of the carapace. The first leg-bearing somite is well exposed, though short. The 



