VALBYTEUTHIDAE ROPER AND YOUNG 



identical with the early larval clubs of Chiroteuthis, the predominant 

 genus of the family. The adult Chiroteuthis club begins to develop 

 in the larval stage along the tentacular stalk proximal to the primary 

 larval club. The primary larval club is eliminated upon metamorpho- 

 sis either by resorption or autotomy (pers. observ.). The striking 

 similarity of clubs of Valbyteuthis and early larval Chiroteuthis is 

 apparent in the illustrations on plate 1b, d, and f, and indicates 

 the close relationship of the two genera. 



Further relationship between these genera is suggested by the 

 close resemblance of the extremely long, weak, ventral arms; they 



Figure 1. — Geographic distribution of Valbyteuthis. 



bear small suckers that are aligned nearly in a single row, and they 

 possess very large lateral membranes. These features give the arms 

 a very distinctive appearance. The characteristic lateral membranes 

 were not mentioned in Joubin's description and did not appear in 

 his illustration, probably due to the poor condition of his specimen. 



Although the adults of the two genera appear to differ considerably 

 in overall appearance (pis. 2a, b, 3), general similarities do exist. 

 In addition to the characteristics already mentioned, both groups 

 have elongate heads, oval fins, and similar arm formulae. 



The larval stages of Valbyteuthis and Chiroteuthis (especially the 

 "doratopsis" type) show even greater similarities, particularly in the 

 following details: very elongate head, long fourth arms, relatively 



