6 JOSEPH A. CLUBB. 



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External characters Height of body-wall 5 '75 cm., diameter of column 4 cm., 

 diameter of oral disc 3 cm., diameter of pedal disc (contracted condition) 2 '75 cm. 



There is no trace of distinctive coloration in the preserved specimen, and no 

 record on the collector's label. The single specimen is poorly preserved, and owing to 

 the thin and delicate body-wall is quite collapsed. The column is studded with 

 thin-walled simple vesicles (PI. 2, Fig. 12) communicating with the coelenterou and 

 arranged in twenty-four vertical and parallel rows, corresponding to the mesenteric 

 spaces. The attachment of the mesenteries may be seen in places, between the rows 

 of vesicles. The vesicles of adjacent rows are arranged alternately, and they increase 

 in size from the proximal to the distal portion of the column (PI. 2, Fig. 12), where 

 the largest are not much inferior in size to and do not differ much in appearance from 

 the tentacles in the preserved and contracted specimen. 



The tentacles are twenty-four in number, arranged in two cycles of equal size, 

 short and somewhat club-shaped. The largest measures 0' 5 cm. in length. The 

 oral disc is slightly furrowed radially and the mouth is large and bears a well-marked 

 hypostome. The oesophagus is short and strongly plicated, and two deep and 

 well-marked siphonoglyphs are present, and are continued some distance below the 

 rest of the ossophagus as distinct lappets. 



The coelenteron is large, and twelve pairs of mesenteries, all complete, are present. 

 Two pairs of directive mesenteries bear -the usual relation with the siphonoglyphs. 

 The single specimen taken is poorly preserved and much of the histological detail is 

 lost. The sphincter is diffuse and endodermal in character, with slightly projecting 

 mesogloeal lamellae shown in transverse section (PI. 2, Fig. 13). The muscles of the 

 tentacles are ectodermal. The muscles of the body-wall (PI. 2, Fig. 14) are feeble, 

 and sections through the vesicles show a similar structure. The ectoderm and 

 endoderm layers consist of relatively high columnar cells (PI. 2, Figs. 13 and 14); 

 but the mesogloea is thin. The mesenteries are very thin and delicate, but transverse 

 sections show a weak but well-marked longitudinal muscle (PI. 2, Fig. 14), the 

 mesogloea in relation with it being thickened and possessing short branching lamellae. 

 The parieto-basilar muscle is small (PI. 2, Fig. 14). 



The specimen is female, and ovaries are found on all mesenteries, including 

 directives, forming broad bands occupying in their widest portions about a third of 

 the width of the mesenteries. Ova in alb stages of development (PI. 2, Figs. 14 

 and 15) are present. 



FAMILY CRIBRINHXE, McMurrich, (1901.) 



ACTINIARIA with a well-developed circumscribed endodermal sphincter ; simple 

 tentacles ; without cinclides and acontia ; verrucac usually present ; adherent base ; no 

 true acroragi, but frequently pseudoaeroragi present. 



