282 



" ENDEAVOUR " SCIENTIFIC RESULTS. 



Another alternative has recently been advanced by Miss' 

 Massy in referring Hoyle's form (she does not mention the 

 older names) to the widespread P. rugosus (Bosc) =granulatus 

 (Lamarck). Whether one adopts this view or not it should 

 be remembered that she has had the immeasurable advantage 

 of access to many of the historic specimens in the Paris and 

 British Museums with which to fortify her opinion. 



The most remarkable feature of the " Endeavour " speci- 

 mens is the ornamentation of the integument. The larger 

 dorsal tubercles shoAv a remarkably symmetrical arran ement 

 which does not seem to have been described by other authors, 

 though it is a conspicuous and constant feature. On the 

 dorsum in the median line appears a series of four large, 

 evenly spaced, branched tubercles, flanked on each side by 

 a similar series of three to four tubercles, the middle one 

 somewhat displaced ventrally, and by a few smaller tubercles 

 below these. The lateral series are so placed with reference 

 to the median that the tubercles have an appearance of being 



arranged in transverse 

 as well as longitudinal 

 rows. A similar tubercle 

 is often borne on the 

 base of each dorsal arm, 

 with a more constant, 

 larger, central one behind 

 them. There is a some- 

 what smaller tubercle at 

 the extreme posterior 

 tip of the body. Above 

 and behind each eye (PI. 

 Ixxxii, figs. 2, 4) is a very 

 large , soft , branched 

 tubercle, accompanied 

 by some 5-7 smaller ones. 

 The variations observed 

 in this general pattern as outlined are only minor. In addition 

 to these major ornaments, the entire dorsal surface of the head 

 and body, and the outer aspect of the arms and mnbrella are 

 covered by numerous, large, crowded papillse (PI. Ixxxii., fig. 3), 

 of characteristic stellate structure as described by Hoyle 

 (1886, p. 81). These papillse are in some specimens, such as 

 E3625, flattened out to resemble a sort of reticulated pave- 

 ment, but seem always unmistakablj^ present, and when well 

 preserved (cf. PI. Ixxix.) are a very beautiful feature. The 

 papillation extends also over the entire ventral surface of the 

 head, body, and funnel over the inner surface of the umbrella, 



0.5 



Fig. 63.- — Poll/pus variolatus ^ [•'>27], 

 three rows of teeth from one side of 

 radula : part camera drawing from a 

 mount in balsam. 



