A NEW TYPE OF AMPHIPODA. 127 



the angle between the posterior and the upper margin is pro- 

 duced into a small triangular process directed backwards. The 

 anterior, moderately narrow end of the plate is inserted on a 

 short and rather narrow joint, which is withdrawn beneath the 

 side-plate of the segment. 



Uropods. — The first pair (fig. 32) differ from those of I. abyssi 

 in two characters : the peduncle is considerably less widened on 

 the outer side of its basal half, and the outer ramus is distinctly 

 broader at the base, but considerably shorter, only half as long 

 as the inner ramus. The second pair (fig. 32) are rather similar 

 to those of I. ahyssi, but the peduncle is even a little broader, 

 with only three oblique rows of spines on the inner side, and the 

 outer ramus is a little longer than the inner. The third pair 

 are more slender than in I. ahyssi, and a separate second joint 

 could not be made out, but its long terminal seta is present. 



Telson. — 'Scarcely so deep as in I. ahyssi and the dorsal setse 

 are longer (fig. 22), otherwise as in the former species. 



BrancliicB. — These are present on the three same pairs of legs 

 as in I. ahyssi, but they are nearly circular in outline (fig. 27, h. ; 

 fig. 29). 



Age and Sex. — The animal appears to be immature, and the 

 sex could not be made out. 



Length. — The specimen measures 1*5 mm. in length. 



Locality. — Gulf of Siam, on the coast of the isl. of Koh 

 Chang, in bottom-material obtained (Jan. 17, 1900) by Dr. Th. 

 Mortensen from corals, 1 fathom. 



JRemarhs. — Among the numerous differences between this 

 species and L. ahyssi, the shape of the "claw" on the three 

 posterior pairs of thoracic legs is, undoubtedly, the most in- 

 teresting. Among the others some may be especially pointed 

 c^t, viz., the shape of the eye-lobes, of the basal joint of the 

 first pair of thoracic legs, shape and armature of the first and 

 especially of the second hand with its finger, finally the shape of 

 the pleopods. 



II. The Essential Characters of the Type. 

 At the first glance the two species appear somewhat similar 

 to the Caprellidae, but on a closer examination it is seen that 

 Lngolfiella is very distinct from that family, so different, in fact, 

 that it is not more related to it than to some other families : it 

 occupies in reality a very isolated position. 



LINN. JOTJRN. — ZOOLOaY, VOL. XXI5. 9 



