284 Mr. n. G. Seelcy on Zoocapsa dolichorliamphia. 



The scutum is four-sided, as in ScalpeUumy but wider from 

 tlie tergal margin to the occhident margin along the straight 

 base than it is high from the basal margin to the apex. The 

 basal margin is slightly inflected. The occludent margin, as 

 in Coronula, is moderately concave from base to apex, the 

 extremity of which is not exposed : in the living genera it is 

 straight or convex. This margin is destitute of the inflexion 

 so characteristic of recent sessile Cirripedes, and therein is 

 more like Scaljiellum. The two remaining margins are 

 straight, make a large angle with each other ; and both join 

 the tergum. The upper margin, seemingly the longer of the 

 two, fits against the beak of the tergum ; the tergal margin 

 articulates with the tergum in the usual way. Externally the 

 scutum was slightly convex and cancelhite. The four-sided 

 form is clearly a consequence of the prolongation of the beak 

 of the tergum, and therefore no evidence of aftinity, since the 

 margin, which here is properly tergal, in Scaliyellum would be 

 lateral and be presented towards tlie upper latus. The species 

 of Balanus with a beaked tergum have the scutum only three- 

 sided, because the beak makes a sliglitly curved continuation 

 of the tergal margin, and not an angular bend in it. 



The tergum is an irregular, subtriangular, trilobed plate, 

 formed of three unequal triangular parts, whose apices termi- 

 nate with a long subcylindrical apex of uniform width, which 

 is bent slightly inward so as to touch the scutum, when that 

 plate meets it at an angle, as is common among the Balanida?. 

 On the basal margin is a deep emargination in its middle 

 third, in the place where the sjjur is developed in Balanus ; so 

 that in this respect it rather approximates to a species of 

 Elminius. This notcli is at the termination of a Avide depressed 

 groove, triangular in outline, forming the middle tliird of the 

 plate ; it widens towards the basal margin, as is characteristic 

 of the tergum in most of the Balanida3. Tlie tliird of the base 

 towards the carinal margin, however, is much prolonged ; it 

 widens, and is rounded at its termination. The carinal mar- 

 gin is straight, except just below the origin of the apex, where 

 it widens so as to present a prominent angle. The scutal 

 margin is slightly inflected, much narrower than in living 

 Balani, with the articulation formed by a very narrow arti- 

 cular groove, margined on the outside by an equally narrow 

 articular furrow, which are adjacent to and extend the whole 

 length of the scutal margin up to the apex. 



Projecting from under the tergum is seen the greater part 

 of another Cirripede plate. It is evidently not tlie other scu- 

 tum, being smaller, nor the other tergum, nor one of the com- 

 partments J yet, from its association with the valves described, 



