REPORT ON THE CRUSTACEA MACRURA. 



683 



generic, seeing how variably the dorsal teeth on the pleon are distributed among the 

 species of the same genus. 



Geographical Distribution. — One of Dana's species was taken at the Ladrone Islands 

 and the other in the Sulu Sea. Of those in the Challenger collection, one was taken off 

 the Fiji Islands and the other off Japan and the Philippine Islands. Stimpson records 

 Thalassocaris fucida, Dana, from the Pacific Ocean. 



Observation. — The species of this genus appear to connect those of the family 

 Pandalidse with those of the family Palsemonidae. 



Thalassocaris danse, n. sp. (PI. CXVII. fig. 1). 



Carapace dorsally smooth, anteriorly slightly compressed, and produced to a rostrum 

 which is rather longer than the carapace and serrate superiorly from the frontal crest to 

 the apex with a series of small teeth. Frontal margin furnished with an antennal tooth. 



Pleon having the somites subequal; third somite posteriorly produced to a large 

 dorsal tooth ; lateral margins of the coxal plates produced to a sharp point which is 

 longest in the first and second and gradually lessens posteriorly ; sixth somite more 

 slender and narrower than the preceding. Telson rather longer than the sixth somite 

 and gradually tapering to a point. 



Ophthalmopoda robust and large rather than long. 



First pair of antennae not reaching beyond the apex of the rostrum. 



Second pair of antennas about as long as the animal. Scaphocerite sharply pointed and 

 armed with teeth on the outer margin. 



First paii* of pereiopoda slender and styliform. Second pair short and robust, 

 Three following pairs longer than the second and terminating in a simple dactylos. 



Pleopoda biramose, terminal pair not longer than the telson. 



Habitat. — Fiji Islands ; at the surface. One specimen. 



The carapace is rounded posteriorly and a little compressed anteriorly, slightly crested 

 and produced to a rostrum that is slightly longer than the carapace, and armed on the 

 upper surface with a regular series of small teeth commencing on the frontal crest and 

 continued to the distal extremity, which is slightly curved upwards. The under margin 



