422 DEPARTMENT OF THE XAVAL SERVICE 



Pterosagitta draco. Stiff. Rather opaque. Fins completely traversed by rays. 7-10-8 

 jaws. Tail percentage, 46-38. Collarette very thick and over whole of trunk. 

 Ovary rodlike. Up to llmm. 



H2. Lateral fins on both trunk and tail. One row of teeth on each 

 side. 

 Ji. Fins extending- to ventral ganglion and largely without rays. 



Eukrohnia hamata. Stiff and moderately slender, 8-11-9 jaws. Tail percentage, 22-32. 

 No collarette. Up to 43mm. 



J2. Fins well behind ventral ganglion, with small inner zone free 

 from rays. 



Krohnitta suhtilis. Stiff and slender. T-10 jaws. Tail percentage, 29-38. No collar- 

 ette. Up to 16mm. 



LITERATURE. 



Apstein, C. 



1911. Chaetognatha. Cons. Perm. Internat., Bull. Trimestr., part 2, pp. 170- 

 175, Plate xxiv. 



Bigelow, H. B. 



1914. Explorations in the Gulf of Maine, July and August, 1912, etc.. Bull. Mus. 

 Corap. Zool., a'oI. Iviii, No. 2. 



1915. Exploration of the Coast Water between Nova Scotia and Chesapeake Bay, 

 July and August, 1913, etc. Bull. Mus. Comp. Zool., vol. lix. No. 4. 



Conant, F. S. 



1896. Notes on the Chaetognaths. Johns Hopkins Univ. Circ, vol. xv. No. 126. 

 Towler, G. H. 



1906. The Chaetognatha of the Siboga Expedition. Siboga-Exped., Mon. xxi. 



1907. Chaetognatha. Nat. Ant. Exped., Nat. Hist., voL iii. 



1896. Plankton of the Faeroe Channel. No. 1. Proc. Zool. Soc, pp. 991-996, 

 Plate L. 



Michael, E. L. 



1911. Classification and Vertical Distribution of the Chaetognatha of the San 

 Diego Region, etc. Univ. Calif. Publ. Zool., vol. 8, No. 3. 



1913. Vertical Distribution of the Chaetognatha of the San Diego Region, etc. 

 Amer. Natur., vol. xlvii, pp. 17-49. 



Murray, J. and Hjort, J. 



1912. The Depths of the Ocean. London, 1912. 



Ritter-Zahony, R. Von. 



1910. Chaetognatha from the Coasts of Ireland. Fish. Ireland, Sc. Invest., 



1910, iv. 



1911. Chaetognathi. Das Tierreich. 



Strodtmann, S. 



1892. Die Systematik der Chaetognathen. Arch. Natur., vol. 58i, pp. 338-377. 

 1911. Die Chaetognathen. Nordisches Plankton, vol. v. 



