508 BEV. E. BOOa WATSOK ON THE 



II. The SoLENOCONCHiA, comprising the Grenera Dentalium, 

 Siphodentalium, and Cadulus. By the Eev. R. BooG Wat- 

 son, B.A., P.L.S., &c. 



[Bead November 21, 1878.] 



The subjoined list is an enumeration of the species of Dentalium 

 referred to in detail. 



Dentalium. 



1. D. capillosum, Jeffr. 10. D. lungitrorsum, Reeve. 



2. D. cBgeum, W. 11. D. compressum, W. 



3. D. ampMalum, W. 12. D. subterjlssum, Jeifr. 



4. D. ceras, W. 13. D. didymum, W. 



5. D. diarrJiox, W. 14. D. yolcoliamense, W. 



6. D. eiitalis, "W. 15. D. dentalis, Linn. 



7. D. leptosceles, W. 16. D.javanum, Sow. 



8. D. circumcinctum, W. 17. D. ensiculus, Jeffr. 



9. D. acutissimum, W. 18. 2). tornatum, W. 



1. Dentalium capillosum, Jefr.; Jeffreys, ^Valorous'' Be- 

 port, Proc. Boy. Soc. xxv. No. 173, 1876, p. 191. No. in list 26. 

 Do. Ann. Sf Mag. Nat. Hist. 1877, xix. p. 153. 



St. II. Jan. 13, 1873. Lat. 38° 10' N., long. 9° 14' W. Setubal. 

 470 fms. Glohigerina- ooze. 1 specimen. 



(?) St. 24. Mar. 25, 1873. Off Culebra Is., St. Thomas, 

 D. W. I. 390 fms. Mud. 



St. 73. June 30, 1873. Lat. 38° 30' N., long. 31° 14' W. 

 1000 fms. Glohigerina- ooze. "W. of Azores. 2 specimens. 



St. 78. July 10, 1873. Lat. 37° 24' N., long. 25° 13' W. 

 1000 fms. Ololigerina-ooze. Off San Miguel, Azores. 1 

 specimen, young, and 2 fragments. 



Mr. Grwyn Jeffreys gives this species as taken by the 

 ' Valorous ' at St. 12, 1450 fms. ; St. 13, 690 fms. ; St. 16, 

 1785 fms. ; by the ' Porcupine,' 1869, Bay of Biscay, 862 fms., N. 

 of Hebrides, 542 fms. ; and he states that Pourtales got it in the 

 Bay of Mexico, off Bahia Honda, in 418 fms. He has described the 

 ribs as " sharp (not rounded)." They rather seem to be sharply 

 cut ; but they are rounded on the top. L. 21 in. B. at mouth 

 0-22, at apex 0-036. 



The young specimen from St. 78 has at the apex on the convex 



