408 THE DECAPODA COLLECTED BY THE " HUXLEY " FROM THE 



DECAPODA NATANTIA. 



PEN-SIDEA. 



Sergestid^. 



Sergestes arcticus, Kroyer. 



Station VIII. Surface. Many, 9-22 mm.* 

 „ X. Surface. One, very small. 



XII. 246 fathoms. Five, 29-35 mm. 



The majority of the specimens only measure from 9 to 15 mm. in 

 length, and the largest (35 mm.) is not half grown. The examples 

 from St. XII were prohably caught in midwater during the ascent of 

 the net. 



STENOPIDEA. 



Stenopid^. 

 Spongicola f Koehleri, Caullery. 



Station XIII. 412 fathoms. Twenty-three, 25-46 mm., and several 

 very young, about 8 mm. 



Prior to the date of the Huxley's cruise, this interesting species 

 was known only from five specimens dredged in the Bay of Biscay in 

 770 fathoms by the Caudan expedition. The additional examples, 

 while in the main confirming the accuracy of Caullery's J description, 

 show a very considerable amount of variation in the spinulation of 

 the carapace and certain appendages. This variation is indeed so great 

 that no specimen in the collection exhil )its precisely the same armature 

 on both sides of its body. The following notes indicate the numbers 

 of spines and spinules observed in some of the more important 

 positions. 



The rostrum bears from 6 to 9 teeth on its dorsal aspect. Ventrally 

 there are two ridges (for the rostrum is triangular in section), each of 

 which is furnished with from to 4 spinules. Occasionally the fore- 

 most spinule is median in position owing to the confluence of the two 

 ridges near the apex. The rounded antero-inferior angle of the 

 carapace bears from 1 to 4 short spines, and from 1 to 4 are situated 

 on the lateral face of the carapace a little behind the margin. At the 



* The measurements of all the Natantia mentioned in this paper were taken from the 

 tip of the rostrum to the apex of the telson. 



t Bouvier (Mem. Mus. Com]). Zool., Harvard, XXVII, 3, 1909, p. 264) gives a useful 

 table for the discrimination of the five species comprised in this genus. 



J " Schizopodes et Decapodesde la Campagne du Caudan." Ann. Univ. Lyon, XW I,. 

 1895, p. 382. 



