ISOPODS OK NORTH AMERICA, 49 



lO. Genus TYPH LAPSE U DES Beddard." 



Eyes absent. No cxop()dit(> present on the tirst two paii's of thoracic 

 appenda*^es. All five pairs of pleopoda present. Abdomen composed 

 of six distinct seg-ments. Antennae with a rudimentary exopodite, 

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

 dite bi-articulate. 



TYPHLAPSEUDES NEREUS Beddard. 



Ti/j)hl(ipseudes nereus BEonARi), Proc. Zool. Soc. Loud., 1<S8(5, Pt. 1, p. 115; 

 Report on the Scientific Results of tlie Expl. Voyage of f I. M. S. Challenger, 

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

 1901, p. 505. 



Locality. — Ofi* 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 an}'^ covering of hairs even on the abdomen; it is 

 wider anteriorly and gradually narrows to the posterior extremity. 



''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 laterall}" 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. 



"The free thoracic segments diminish gradually 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 anteriorl}" in 

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

 two segments are furnished with a short spine, ver}^ broad at its base, 

 which is situated about halfwa}^ 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 lamelhe. Of the a))dominal segnnents the first pair are 

 subcqual, but diminish gradually in l)readth: they are furnished 

 with small epimera, terminating in a pointed extremity and directed 

 backward. 



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



28589—05 4 



