138 PROCEEDINGS OF THE ACADEMY OF []\Iarch, 



The following are the measurements of the largest specimen: 

 total length three inches, diameter of head one and one-half inches, 

 greatest width of body one-half inch, greatest width of foot one- 

 fourth inch, greatest height of body three-fourths inch. No pig- 

 ment is visible in the skin of living animals, though the body wall 

 has a milky appearance and is sufficiently transparent to show the 

 light blue and reddish viscera within. 



External Features. — The body (PL XI, fig. 1) comprises two 

 distinct divisions, the head and body proper. The head presents 

 the appearance of a low vault or cowl provided with two dorsal tenta- 

 cles, two sets of marginal tentacles and on its under surface bears 

 the mouth. Unlike CMorcera leonina, the dorsal tentacles are not 

 retractile, and in preserved material are plain, muscular, foliaceous 

 outgrowths. Gould states that the tentacles of C. leonina bear on 

 their anterior margins "an opaque, whitish papilla, presenting 

 something of a spiral or lamellar structure." Nothing of the kind 

 has been found to exist in the present species. 



The marginal head tentacles form two series, an outer set com- 

 prising from fifty to seventy-five large, slender processes, and an 

 inner fringe formed of much smaller outgrowths of approximately 

 double the number. Each of these cirri is provided with a nerve 

 (PI. XI, fig. 2) and gives evidence of being a tactile organ, though 

 observations along this line were very incomplete. 



The mouth presents the appearance of a longitudinal slit (PI. XI, 

 fig. 1) placed near the posterior margin of the head, and therefore 

 in close proximity to the anterior margin of the foot. Its posterior 

 border may be said to be formed by the free border of the head, 

 which here forms a deep angle usually devoid of the larger type of 

 tentacle. Laterally and anteriorly the oral opening is surrounded 

 by prominent, swollen lips. In living and in certain preserved 

 specimens, the head region for some distance beyond the lips forms 

 a prominent swollen area, occasionally thrown into temporary 

 ridges. Sections show this area to be highly vascular. Unfortu- 

 nately, more pressing duties made it impossible to make careful obser- 

 vations on living animals, and an exact description of the normal 

 appearance of this area is now impossible. It may be added that 

 in Gould's figure of C. leonina the mouth occupies a central position 

 beneath the cephalic vault or cowl, w^hose tentaculate margin encom- 

 passes it at a considerable distance. 



The body, separated from the head by a distinct cleft forming a 

 neck, is roughly conical in form, and ventrally is traversed throughout 



