10 MUSEUM, BEOOKLYN INSTITUTE OF ARTS AND SCIENCES. 

 Turritopsis nutricula, McChady. 



MoObady, J., 1857; Gymn. Charleston Harbor, p. 35, Pis. IV, V, VIII, Fig. 1. 

 Modeeria multitentaoula, Fbwkbs, J. W. 1881; Bull. Mus. Comp. Zool. at Harvard Coll., 

 Vol. VIII, p. 149, PI. Ill, Figs. 7-9. 



Bbooks, W. K.. 1886; Mem. Boston Soc. Nat. Hist., Vol. Ill, p. 388, PI. 37. 



Bell 4 mm. high. Pear-shaped, with thin walls. 40-50 marginal tentacles, 

 each with an ocellus on the outer side near the basal bulb. Four narrow 

 radial canals. Manubrium wide, flask-shaped and one-half as long as the 

 depth of bell cavity. Proximal part of manubrium contains large vacuolated 

 cells, through the midst of which the four radial canals extend into the gas- 

 tric portion of the manubrium. Mouth at end of a short cylindrical tube, and 

 surrounded by four radially-situated nematocyst-bearing knobs. Gonads 

 within the manubrium. Entoderm of manubrium dull yellow streaked with 

 brownish orange. Ocelli of tentacle bulbs brown or orange. The hydroid, 

 discovered by Brooks, is Dendroclava. Medusa common from Cuba to New- 

 port, Rhode Island. Eare at the Bahamas in summer. 



Lymnorea Alexandri, sp. nov. 

 Figs. l-5a, Plate I. 



Named in honor of Alexander Agassiz. Bell 4 mm. high, 3 mm. broad, 

 with vertical sides, flat top and thin walls. Thirty-two slender tentacles with 

 tightly coiled ends and large basal bulbs. A black ectodermal ocellus lies 

 upon the outer side of each tentacle-bulb. The velum is well-developed. The 

 four radial canals are straight and slender but slightly swollen in the mid- 

 regions of their lengths, where their inner sides are lined with gland-cells. 

 (Fig. 5% Plate I.) 



The manubrium is flask-shaped and about one-half as long as the depth 

 of the bell-cavity. The distal part of the manubrium adjacent to the points 

 of entrance of the four radial canals is composed of highly vacuolated cells. 

 The mid region of the manubrium is cruciform in cross section and the 

 mature genital products are found in the ectoderm. The mouth is at the ex- 

 tremity of a short neck, and is surrounded by four oral tentacles, each of 

 which branches dichotomously three times, and terminates in eight nemato- 

 cyst-bearing knobs, making in all thirty-two of these knobs surrounding the 

 mouth. The entoderm of the manubrium and tentacle-bulbs is dull, flesh- 

 colored pink. In the youngest medusa seen the bell was 0.6 mm. in diameter, 

 and had only four oral tentacle knobs, four marginal tentacles and four rudi- 



