PENNATULIDA. 



Foundland, Nova Scotia, and the northernmost of the United states (as far as off Nantucket Island 

 and Martha's Vineyard). To these localities are now to be added the banks round the Faeroe Isles. 

 It has been taken at depths from 50—1255 fathoms'). 



Pennatula prolifera n. sp. 



PI. II, figs. 15—24. 



From two stations in Davis Straits, 24 and 36, we have obtained a Pennaiula-species in ver\- 

 large numbers, from the former station about 40 specimens, from the latter upwards of a hundred: 

 but all the specimens are young ones, several of them as small and apparently as young as the 

 vouugest known stages of Peniiatula phosphorca^)\ even the largest and most developed specimen is 

 still little developed, as will be .shown more particularly below, so far as the pen's provision of polyps 

 is concerned. It is a very difficult thing therefore to characterize the species; or, to speak more cor- 

 rectly, it is impossible to diagnose it briefly by such features, as are elsewhere used in distinguishing 

 species within the genus Pennatula. That the species is a new one not hitherto described, will be 

 obvious, I think, from the following description, in which I shall give an account of the peculiar mode 

 of propagation in this species which has led me to give it the specific name prolifera. 



All the specimens were white, with the exception of two from St. 36, which were light-red; 

 but these also have now turned as white as the others in spirit. 



The largest specimen (from St. 24) has to some degree the penniform appearance (figs. 15, 16). 

 The total length is 35""™, in which the rhachis accounts for i8™"\ measiired from the terminal zooid 

 (see below) to the lowermost polyp-bud, the peduncle i5'/2'""; the breadth of the pen is 4.5""" (the 

 polyps being pressed in against the stem); the rhachis itself is ca. 1.5""" broad, the terminal bulb of 

 the peduncle is 2.5'"" long and ca. 1.5""" broad. On either side of the rhachis are eight distinct wings 

 and below these four rudimentarv wiuo-s. 



The calyx-mouth of the polyps is provided with 8 long and strong spines supported by long 

 spicules. The form of the calyx, as is ordinarily the case in the genus, is somewhat different accord- 

 ing to the degree of retraction; when the polyps are quite retracted, the calyx-teeth are closed and 

 the whole calyx has a lengthened oval form reminding one of a narrow grain of barley. The longest 

 calices are 5""" long and ca. i-"" broad. The tentacles are on the aboral side provided with longi- 

 tudinally arranged spicules, both on the stem and the lateral branches. 



With regard to the arrangement of the polyps it has first to be pointed out that no terminal 

 polyp is present: the pen ends above in two polyps placed (almost) side by side and equalh- developed; 

 between^ their bases the upper end of the rhachis itself is found, formed b>- a large zooid (with two 

 calyx-points). Each of these two uppermost polyps forms a wing (I). This uppermost pair of wings 

 is separated from the next jxiir (II) by a somewhat long part of the rhachis, this latter pair again 

 by a somewhat shorter distance from the third pair (III), whilst the following pairs (IV— YIII) follow 

 one another more closely. 



■) Verrill: Rep. U .S. Fish. Comm. 1883, p. 509. 

 ') iMffured bv Jungersen. [888, PI. V, figs. 1—2. 



