356 LITHOTRYA CAUTA. 



other parts. The spines on the first three pairs of cirri 

 are coarsely serrated. 



Caudal Appendages (PI. X, fig. 23), with numerous 

 tapering segments, almost equalling one and a half times 

 the length of the pedicel of the sixth cirrus. Each seg- 

 ment is elongated and somewhat constricted in the middle, 

 with its upper edge (fig. 24) crowned with short spines ; 

 in a full-sized specimen there were seventeen segments. 



2. LlTHOTRYA CAUTA. PI. VIII, fig. 3. 



L. scutis terga ample obtegentibus : carina intus concavd: 

 rostro squamarum subjacentium latitudinem vise cequante : 

 lateribus, squamas subjacentes sesquitertio super antibus; 

 superficie interna late ellipticd: pedunculi squamis supe- 

 rioribus verticillum secundum pcene quadruplo superantibus. 



Scuta largely overlapping the terga : carina internally 

 concave : rostrum hardly as wide as one of the subjacent 

 scales : latera with their internal surfaces broadly ellip- 

 tical, as long as two and a half of the subjacent scales : 

 upper scales of the peduncle nearly four times as large 

 as those in the second whorl. 



Mandibles with an equal number of pectinations 

 between the first, second, and third main teeth : maxillae 

 notched, edge nearly straight : posterior rami of the 

 second and third cirri, with their basal segments not 

 paved with bristles : caudal appendages slightly exceeding 

 in length the pedicels of the sixth cirrus. 



New South Wales, Australia, imbedded iu a Conia, (uuique specimen,) 

 Mus. Stutchbury. 



. Valves thin, white, translucent; upper layers of growth 

 well preserved, excepting on the terga. A large portion 

 of the carina projected freely. The teeth on the projecting 

 margins of the growth-layers are broad, blunt, and often 

 stand rather distant from each other. 



Scuta (PI. VIII, fig. 3 a) } triangular, internally concave, 



