284 Mr. N. Colgan on 



were seen to issue in the normal way from the oviduct in the 

 angle between two adjacent arms. At 1 P.M. the pale blotch 

 on one of the arms was seen to accompany the swelling, 

 which slowly travelled along the arm towards the ruptured 

 extremity, and a further extrusion occurred as soon as the 

 swelling and its accompanying pale blotch had reached the 

 point of rupture. About the same time the tip of the fourth 

 ray became ruptured and a portion of the cseca was extruded 

 at the moment when a slowly travelling swelling had reached 

 the tip. At four minutes to 7 p.m. on the same day a pro- 

 minent swelling was seen to have travelled along the fifth 

 ray almost to the tip, and watching this narrowly the beginning 

 of a protrusion of the cceca, which ultimately reached to a 

 length of 4 mm., was seen to take place at the moment when 

 the swelling reached the extremity of the arm. While the 

 extrusion was being slowly effected — it occupied fully four 

 minutes — the unattached sucker feet near the tip of the ray 

 were seen to be in vigorous spasmodic action, and the 

 swelling proceeded to travel backwards along the ray to- 

 wards the disk. The propagation along the rays of these 

 swellings or waves of inflation was very slowly effected, the 

 average of several observations giving a rate of 6 mm., or, 

 say, a quarter of an inch per minute. 



By 8 P.M. on the 24th April one pair of cseca was found 

 to be fully extruded from an arm of this second specimen of 

 Crihella. It was detached and placed in spirit and the 

 following day the animal was treated with chloral and then 

 preserved in spirit so as to show the unequal extrusion of the 

 cseca from the tips of the other arms. In this case no gonada 

 were observed to have been extruded from the ruptured arm- 

 tips, as they probably would have been had the process of 

 self-evisceration been suffered to proceed. 



In October 1909, further observations were made on a 

 third individual of this species, a regular 5-rayed specimen 

 2i inches in diameter over all, which 1 iiad dredged in 

 10 fathoms off Bullock on the 25th of the month. On the 

 morning of the 29th, four days after the capture, slight 

 swellings and constrictions were noticed on some of the arras, 

 and on the 31st two distinct knots or abrupt swellings 

 appeared on one of them. For ten days these swellings 

 continued to appear and to pass in very slowly propagated 

 waves along the arms without any rupture being effected. 

 Finally, at 8.30 a.m. on the 11th November, a minute 

 rupture of the integument was observed on the upper surface 

 of one of the arms near its tip, and from this breach a sni«ll 



