Boone, Coelenterata, Cruises of "Eagle" and " Ara," 1921-28 33 



the margin. The tentacles of this series are furnished with wart-like 

 clusters of nematocysts, and near the distal end, on the aboral side, 

 there is an elongate, pad-like cluster of nematocyst cells, having a 

 sucker-like appearance and serving as a strong adhesive organ, 

 enabling the medusa to fasten itself to stones, etc. The exumbrella 

 tentacles are 34 in number and arise from the bell margin ; are about 

 four times as long as the bell diameter, frequently retracted into cork- 

 screw like curls and having a very powerful longitudinal muscle stripe 

 on the inner side while the outer side is regularly banded by trans- 

 verse half-rings of nematocysts. The tentacles terminate in a knob-like 

 cluster of nematocysts and on their inner side there is a pad-like clus- 

 ter of large cells which may serve as a weak adhesive organ. The 

 exumbrella margin between the tentacles is in the form of small, 

 rounded papillae. Above the ring-canal, on its inner side, are a series 

 of lithocysts, a pair between the base of each velar tentacle; making 

 a total of from 64 to 108 lithocysts. There is a spherical concretion 

 in each lithocyst. There are four straight radial canals and twenty- 

 eight to forty branches which extend inward from the ring canal and 

 end blindly in the bell. The four gonads are papilliform, laterally 

 reflected and develop on the outer halves of the radial canals. The 

 manubrium is tubular, elongate reaching about three-fourths of the 

 depth of the bell, and is cruciform in cross-section and has four out- 

 curved lips. 



References: Halicalyx tenuis Fewkes, Bull. Mus. Comp. Zool., 

 vol. 9, p. 277, pi. 7, fig. 15, 1882.— Mayer, Bull. Mus. Comp. 

 Zool., vol. 37, p. 63, pis. 5, 6, figs. 12, 13, 1900.— Goto, Mark 

 Anniversary Volume, p. 15, 1903. 



Olindias tenuis Browne, Fauna and Geol. Maldive Archipelagoes, 

 vol. 2, p. 737, 1904.— Mayer, Mem. Nat. Sci. Brooklyn Inst. Mus., 

 vol. 1, p. 23, pis. 5, 6, figs. 50-59, 1904; Medusae of the World, 

 Publ. 109, Carnegie Inst. Wash., vol. II, p. 354, 1910.— Bigelow, 

 H. B., Mem. Mus. Comp. Zool., vol. 37, p. 109, 1909. 



Order: NARCOMEDUSAE. 



Family : AEGINIDAE sens. ampl. 



Genus : SOLMISSUS Haeckel. 



Solmissus albescens (Gegenbaur). 



Plate 5. 

 Type: Collected in the Mediterranean Sea; depository not stated. 

 Distribution : An abundant species in the Mediterranean Sea. 



