Occasional Papers of the Muscuui of Zoology 9 



five, 279) ; anal ray-chambers, 36 to 40 (average of six, 38). 

 Dorsal ray-chambers about two or three times as high as long ; 

 dorsal fin about one-eighth as high as body. Anus near middle 

 of lower caudal lobe; origin of this lobe about midway between 

 tip of tail and atriopore. Postanal length, 8.5 to 11.5 in total. 

 Preatrioporal length, 2.4 to 2.7 times postatrioporal length. 

 Myotome f ormiila : 36 to 40+14 to 16+9 to 12=60 to 64 (in 

 type-material) ; 36 to 38+13 or 14+11 to 15=61 to 64 

 (according to Andrews, 1893). Maximum length, 5.3 cm. 

 (Andrews). 



9. Branchiostoma bermudae Hubbs, new species 



Brancliiostoma liibriciiiii Goode (1877). 



Branchiostoma caribaciiin Bristol and Carpenter (1900) ; Verrill 

 (1902) ; Bean (1906). 



Branchiostoma caribbacum Barbour (1905) ; Parker (1908; and so 

 forth). 



Type-material: — Holotype, from Bermuda, Cat, No. 55145, 

 Museum of Zoology, University of Michigan; donated by Dr. 

 W. J- Crozier. Paratypes, all from Bermuda, were collected 

 by Goode, Bean, Mowbray, Crozier, and Arey. They are 

 deposited in the following institutions : United States National 

 Museum, INIuseum of Zoology, Field Museum of Natural His- 

 tory, Philadelphia Academy of Natural Sciences, Stanford 

 University, and the Bermuda Biological Station. 



Status: — -The Bermuda lancelet is well distinguished from 

 the four other species of the North Atlantic, differing in having 

 fewer ray-chambers in the fins, a shorter tail, and so forth. 

 In some respects it resembles most closely the temperate South 

 American species, B. platac, from which it differs, among other 

 respects, in having about one hundred fewer dorsal ray- 

 chambers (one of the characters heretofore overlooked in the 

 systematic study of lancelets). 



Diagnosis: — Ray-chambers relatively few: in the dorsal fin, 



