ISOPODS OF NORTH AMERICA. 49 



1O. Genus TYPHLAPSEUDES Beddard. 



Eyes absent. No exopodite present on the first two pairs of thoracic 

 appendages. All five pairs of pleopoda present. Abdomen composed 

 of six distinct segments. Antennse with a rudimentary exopodite, 

 consisting of a single long joint. Pleopoda well developed, the exopo- 

 dite bi-articulate. 



TYPHLAPSEUDES NEREUS Beddard. 



Ti/phlapseudes nereus BEDDARD, Proc. Zool. Soc. Lond., 1886, Pt. 1, p. 115; 

 Report on the Scientific Results of the Expl. Voyage of H. M. S. Challenger, 

 Zool, XVII, 1886, pp. 112-113. RICHARDSON, Proc. U. S. Nat. Mus., XXIII, 

 1901, p. 505. 



Locality. Off Sombrero Island. 



Depth. 450 fathoms. 



"This species is represented by a number of individuals dredged in 

 the North Atlantic from a depth of 450 fathoms. The average length 

 of the species is about 10 mm. The body is flattened and depressed, 

 smooth, without any covering of hairs even on the abdomen; it is 

 wider anteriorly and gradually narrows to the posterior extremity. 



u The head and the first segment of the thorax, which are of course 

 fused together and form a cephalic shield, is flattened in front, but 

 convex laterally and behind. The frontal margin projects as a short, 

 sharp rostrum; behind the insertion of the antennary organs is a 

 triangular ocular lobe pointed in front; it has no trace of any optic 

 structures; behind this again is another shorter, triangular, pointed 

 process; more posteriorly the lateral margins of the cephalic shield 

 are convex outward. 



u The free thoracic segments diminish gradualh r in breadth, but 

 increase in length up to the fifth; the sixth is not .only narrower, but 

 shorter than the fifth. They are all furnished with very minute epi- 

 mera, those of the first segment are larger, and project anteriorly in 

 the form of a short spine. The lateral margins of all but the first 

 two segments are furnished with a short spine, very broad at its base, 

 which is situated about halfway between the articulation of the limbs 

 and the anterior margin of the segment. In the sixth (and last) seg- 

 ment of the thorax this spine is almost obsolete. In the ventral 

 surface of the thoracic segments is a median spine. 



"In the female the 'first four of the free thoracic segments have 

 ovigerous lamellae. Of the abdominal segments the first pair are 

 subequal, but diminish gradually in breadth; they are furnished 

 with small epimera, terminating in a pointed extremit} 7 and directed 

 backward. 



See Beddard for characters of genus. Challenger Report, XVII, 1886, pp. 111-112. 

 2858905 i 



