Calkins. — Hydroids. 
PLATE 1. 
Fig. 1. Tubularia larynx. Nat. size. a. Hydranth with gonophores. X 18. 
Fig. 2. Coryne mirabilis. Nat. size. a. Hydrocaulus. X 18. b. Medusa- 
bud. X 80. 
Fig. 3. Perigonimus repens on leg of Pisa. Nat. size. a. Hydrocaulus. Xl8. 
b. Hydranth. X 80. c. Medusae-buds. X 80. d. Hydranth. X 80. 
Fig. 4. Halecium wilsoni. Nat. size. a. Male gonophores. X 18. b. Hydro¬ 
theca. X 80. 
Fig. 5. Halecium densum. Nat. size. a. Portion of hydrocaulus. X 18. b. 
Hydranth. X 80. c. Hydrotheca. X80. 
Fig. 6. Campanularia johnstoni. Nat. size. a. Portion of hydrocaulus. X 18 
b. Hydrotheca and hydranth. X 80. c. Gonosome. X 80. 
Fig. 7. Campanularia johnstoni var. X 80. 
